SDR11-WInnComm Papers and Presentations
29 November - 2 December 2011
Washington, DC

Comprehensive downloads:

Paper and Presentation Abstracts:

(paper and presentation downloads next to talk title)

Tutorial 1A: White Nail: A Software Defined Radio/Cognitive Radio Air Interface Innovation
Dr. Donald Steinbrecher (NAVSEA, RI, USA)

Tutorial 1B: Design and Application of a Hilbert Transformer in a Digital Receiver (paper) (presentation)
Matt Carrick (Northrop Grumman, Chantilly, VA, USA; [email protected]); Doug Jaeger (Northrop Grumman, Chantilly, VA, USA; [email protected]); fred harris (San Diego State University, San Diego, CA, USA; [email protected])

Tutorial 1C: Prototype Implementaion of a Real-­‐ Time 8x8 MIMO LTE-­‐Advanced Link (presentation)
Amal Ekbal, Ph.D. (National Instruments, USA)

QoSMOS Workshop (presentation)
Dr. Roland Beutler

Workshop 1E, 2E: Open Source (presentations)

Workshop 1F, 2F: Regulatory (presentations)

Tutorial 2A: RF System Aspects for SDR (presentation)
Dr. Ruediger Leschhorn (Rohde & Schwarz, Germany)

Session 2B: Receiver Design - Part 1

Communications Systems Design in Mathematica (presentation not available)
Daniel S Iancu (Optimum Semiconductor Technologies & Tampere University of Technology, Tampere, Finland, USA)

Abstract - Mathematica is a high level symbolic computing environment suitable for modern communications systems design. In this tutorial we introduce Mathematica as a programming environment for communications system design. We walk through a simple OFDM example and demonstrate useful features of Mathematica for implementing communications systems. The participants may take the Mathematica notebook provided as a starting point for their own system designs.

Razor[TM]: Advanced Architecture for Thumb-Sized Software Definable Radio (paper) (presentation)
Clark Pope (DRS Signal Solutions, USA)

Abstract - This paper introduces a novel software definable radio (SDR) architecture, called Razor[TM]. The Razor[TM] is a thumb sized SDR composed of an off the shelf processing module mated to a low cost, rf-asic based receiver chain. The processing module contains a DSP, 512MB ram, secure digital card, million gate FPGA, and USB interface. The receiver chain consists of a ceramic preselecting filter, single chip upconverter and LO, saw filter, and integrated downconverter and ADC. It can be configured to cover 20 to 2400 MHz with bandwidths up to 40 MHz and performance greatly superior to conventional direct conversion implementations. The device looks like a standard USB cellular modem but houses a complete Gnuradio based software definable radio system. The device can plug into any PC USB port or operate stand alone.

Classification of Multiple Signals Using 2D Matching of Magnitude-Frequency Density Features (paper)
Aaron Roof (University of Buffalo & Vanteon Corporation, USA); Adly T. Fam (The State University of New York at Buffalo, USA)

Abstract - Signal classification is an important function of modern communication systems in Software Defined Radio (SDR) applications. The ability to quickly recognize the type of received signals allows a system to automatically adapt the processor to properly decode the signals. Many classification techniques assume that the received signal space is occupied by only one signal, and that the frequency of operation is known. However, in some systems, the receiver may be completely blind to the number and characteristics of signals within the bandwidth of interest. The technique introduced in this paper proposes the collapsing of localized magnitude peaks from consecutive short time Discrete Fourier Transform (DFT) bins into magnitude histograms to create a two dimensional image of the frequency-magnitude density of the received signal space. This image can be a useful visualization tool in the characterization of the signal space in user assisted modes of classification. Alternatively, the process could be automated by utilizing pattern recognition and image processing algorithms.

Low complexity MMSE interference cancellation for LTE uplink MIMO receiver (paper) (presentation)
Bei Yin (Rice University, USA); Joseph R. Cavallaro (Rice University, USA)

Abstract - LTE was proposed to support high data rate. Because of the low peak-to-average power ratio (PAPR) of SC-FDMA, SC-FDMA is used in the LTE uplink. In the LTE base station, frequency domain equalizer (FDE) is adopted to achieve good performance in the receiver. However, in multi-tap channels, the residual interference after FDE still remains and degrades the performance. This becomes severe in equal tap channels. In this paper, we propose a low complexity minimum mean square error (MMSE) interference cancellation. After MMSE-FDE, our scheme performs interference cancellation by using the interference regenerated from the selected detected symbols. Then MMSE-TDE is applied to the signal. Our scheme can cancel both inter-symbol interference and inter-antenna interference. The simulation results show our scheme can bring up from 2 to 8 dB gains in different channels. It only adds up to 7.2% computational complexity to the receiver.

SISO and MIMO OFDM Physical Layer Algorithms on a Heterogeneous Multiprocessor Platform - Implementations and Mapping Exploration (paper)
Venkatesh Ramakrishnan (RWTH Aachen University, Germany); Marc Adrat (Fraunhofer FKIE / KOM, Germany); Gerd H. Ascheid (RWTH Aachen University, Germany); Markus Antweiler (Fraunhofer FKIE, Germany)

Abstract - This paper presents the physical layer implementation and mapping exploration of a single input single output (SISO) and multiple input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) systems on a commercial heterogeneous multiprocessor hardware platform. The SFF SDR development platform [1] from Lyrtech is used as the hardware platform in this paper. It consists of a TMS320DM6446 system-on-chip with a ARM926 core and a TMS320C64x+ DSP core from Texas Instruments and Virtex-4 SX35 FPGA from Xilinx. In order to enhance both portability and efficiency, the waveform development process uses the Nucleus methodology [2]. This methodology is library based and adopts a model driven architecture (MDA) design process. The tradeoffs between portability and efficiency are analyzed by efficiently implementing the computation intensive components of the physical layer, e.g. by using hand optimized assembly code in case of DSP.

Session 2C: Cognitive Radio and Dynamic Spectrum Access - Part 1

Cognitive and Engineering Aspects of Communications Recovery after Large Incidents (presentation)
Daniel Devasirvatham (SAIC, USA)

The awesome power of large natural disasters or man-made incidents could compromise civilian and emergency communications over a large area. Traditional techniques concentrate on building stronger terrestrial infrastructure to withstand such events; but these are often overcome. Satellites are used as back-up or for emergency communications recovery. However, these may not have sufficient spatial capacity to serve a large concentrated user base, and users may not have sufficient terminals to use them or be conversant with their use in an emergency. Consequently, command, communications, control, and situation awareness are compromised. An integrated methodology for communications recovery was proposed in. This described a phased approach, starting with satellite communications if necessary, and then transitioning to airborne relays. These would be gradually brought lower down to quickly substitute infrastructure and to re-establish ground communications while increasing spatial capacity.

Statistical Framework for Parametric Optimization of Cognitive Radio Systems (paper)
Ashwin Amanna (Virginia Tech, USA); Daniel Ali (Virginia Tech, USA); Manik Gadhiok (Virgnia Tech, USA); Matthew J Price (Virginia Tech, USA); Jeffrey Reed (Virginia Tech, USA)

Abstract - Enhancing access to radio spectrum is a growing need across the country that cognitive radio (CR) can address. CR systems incorporate learning and decision making into wireless and networking systems with the goal of improving performance and interoperability. Optimizing radio and cognitive engine parameters based on operating performance is a crucial requirement. This step is also a needed element within functional testing and overall evaluation for validating overall systems and specific algorithms. However, the realities of limited time, manpower, and resources require efficient methodologies for performing these tasks. While CR techniques continue to advance, functional testing methodologies remain largely stagnant and rely on ad hoc approaches relevant to a specific platform and application space. Recent CR testing methods are briefly surveyed in this paper.


Enabling Cognitive Radio Situational Awareness- A Tactical Wireless Channel Multistate Model (paper) (presentation)
Glenn Prescott (University of Kansas, USA); Kenneth Brown (Johns Hopkins University, USA)

Abstract - Warfighters, homeland defenders, and emergency responders require managed ubiquitous, end to end, multimedia communication to deliver right information, to the right place, at the right time. End to end communication is typically delivered via federated systems of wired and tactical wireless communication networks vulnerable to time-variant wireless channel conditions. Time variant tactical wireless channel conditions include: 1) limited SNR due to low power, excessive range and/or noise, 2) worst-case fading losses exceeding 30 dB, 3) time dispersion due to multipath, 4) frequency dispersion due to mobility, 5) interference due to adjacent or co-channel transmissions, and 6) hostile jamming. These tactical wireless channel conditions can render legacy fixed configuration communication processing ineffective. This paper surveys published wireless channel multistate models and discovered that input/output multistate models lack state definitions directly linked to channel dispersion and conditions such as frequency selectivity and/or time selectivity.

Session 2D: Test and Measurement - Part 1

Using Field to Lab Testing to Connect Design, Manufacture and Deployment of SDR and CR with Real World Test (presentation)
Erik Org (Azimuth Systems, USA)

Abstract - The ultimate test for a developer or test engineer is one that accurately captures the user experience in a controlled, repeatable, and cost-effective way. The benefit of such a test is that devices and systems will work as expected when delivered to the end users. The typical solution -- drive testing -- can be very expensive and time consuming. Test solutions that bring the real world into the test lab with effective and easy-to-use implementations are precisely what are needed to rapidly assess and benchmark the performance of innovative technologies such as software defined radio (SDR) and cognitive radio (CR). Often, however, standard channel models are not sufficient to accurately benchmark device performance before a device is deployed to the field. Situations that arise in the field, such as "Rising Pilot" where a device under test (DUT) is briefly exposed to high power pilot from an adjacent base station because of the urban landscape, can result in unintended consequences. The ability to identify, map and playback these scenarios enables test engineers to more easily evaluate DUT performance over a wide range of unique RF conditions.


A Real-Time Multi-Path Fading Channel Emulator Developed for LTE Testing (paper) (presentation)
Elliot Briggs (Texas Tech University, USA); Brian Nutter (Texas Tech University, USA); Dan McLane (Innovative Integration, Inc., USA)

Abstract - When developing a communications system, it is useful to perform tests in channel environments in which the system is intended to operate. Many modern mobile communications systems must be tolerant to high mobility and fast-changing channel conditions, which makes field testing difficult. In order to test specific channel conditions, or repeat time-varying sequences that occur in the channel environment, it is useful to have a programmable system that can emulate the conditions found in an actual time-varying radio channels in real-time. In the 3GPP long term evolution (LTE) standard, 3 channel power-delay profiles have been defined for conformance testing, each with varying mobility. An FPGA-based channel emulator has been developed that conforms to the LTE models, yet is flexible enough to allow the user to define their own model if desired. The channel emulator is built around flexibility, allowing the user to define both the power-delay profile as well as the maximum Doppler frequency with high resolution.


A Hybrid DSP and FPGA System for Software Defined Radio Applications (paper) (presentation)
Volodymyr Podosinov (Virginia Tech, USA); Majid Manteghi (Virginia Tech, USA)

Abstract - Software defined radio is vastly researched field right now, due to the fact that given one type of hardware, multiple radio personalities can be implemented. There are a few commercial and government companies who already use the concept of software defined radio in their products. Researches use software defined radio to study the field of cognitive radio, and to research new algorithms. Currently, there are a few options on the market for software defined radio for research. USRP (Universal Serial Radio Peripheral) from Ettus Research LLC is one of them. The platform costs $700 and provides analog front end, with FPGA inside for some filtering and up/down-conversion. Ettus Research recently introduced USRP2 that costs $1400 and provides more capabilities. Rice University makes WARP platform based around FPGA, but it costs $8500. This research introduces a new platform for software defined radio research that is based around DSP and FPGA, and allows for quick interchange of RF front ends, similar to USRP platform. Compared to USRP platform, the platform is embedded and does not require PC to generate or receive data.


Cognitive Radio Testing Using Psychometric Approaches (paper)
Carl B. Dietrich (Virginia Tech & Wireless @ Virginia Tech, USA); Edward Wolfe (Pearson & Assessment & Information Group, USA); Garrett Vanhoy (University of Arizona, USA)

Abstract - Cognitive radios promise efficient spectrum use, but their flexibility complicates testing. We propose to improve cognitive radio development and testing using approaches developed for efficiently measuring and testing human cognitive characteristics.Cognitive radio testing requirements, applicable psychometric approaches, and a planned software-controlled cognitive radio testbed are described.

Session 3A: SDR Processors

Comparison Of Processor Architectures For LTE Channel Estimation (paper) (presentation)
Omer Anjum (Tampere University of Technology, Finland); Teemu Pitknen (Tampere University of Technology, Finland); Jari Nurmi (Tampere University of Technology, Finland)

Abstract - Software-Defined Radio (SDR) architecture has been researched for decades by the industry and academia in terms of flexibility, programmability, power, speed and area to answer the big challenges of rapidly growing communication industry. Achieving GOPS (Giga Operations per Second) in the baseband processing of upcoming standards like LTE, with a few hundreds of milliwatts power budget and flexibility enough to cope with future needs without modifications in the hardware is one of the key challenges. In this paper, we are going to present TTA (Transport Triggered Architecture) as one of the potential candidates for SDR platforms. As the case study, we are going to implement channel estimation for LTE sub-frame with 100 RBs (resource blocks) (20 MHz system bandwidth) on TTA and will compare it with different architectures (RISC, DSP, and Xentium reconfigurable core) presented by the industry and academia. In order to correctly demodulate the OFDM symbol it is very important to make a good estimate for the response of the channel and equalize the distortions caused to the transmitted signal.


MIMO OFDM transceiver for a Many-Core Computing Fabric - A Nucleus based Implementation (paper) (presentation)
Torsten Kempf (RWTH Aachen University Germany, Germany); Gerd H. Ascheid (RWTH Aachen University, Germany); Aamir Ishaque (RWTH, Aachen University Germany, Germany); Daniel Guenther (RWTH Aachen University Germany, Germany)

Abstract - In this paper we analyze the potential as well as the limitations of Many-Core Computing Fabrics (MCCFs) when implementing Software Defined Radio (SDR) applications. These MCCFs consist of multi-core computing clusters that include heterogeneous processor cores and can be equipped with application specific accelerators. We focus on the computationally intensive baseband processing of modern wireless communication standards. Investigations are carried out for an implementation of a MIMO OFDM transceiver for which the IEEE 802.11n standard serves as reference regarding frame structure and timing requirements. To cope with the computational complexity and tight real-time constraints while maintaining easy porting of the investigated transceiver, it has been developed according to the Nucleus concept. Following this, a thorough analysis of the application is conducted to determine the critical algorithmic kernels (Nuclei) contained within the transceiver. Efficient implementations (Flavors) of these Nuclei for the MCCF have been developed.


Vector-Based Acceleration in the IBM PowerEN Processor To Enable Software-Defined Radio (paper) (presentation)
Jeff H. Derby (IBM, USA); Timothy Heil (IBM Systems & Technology Group, USA); Michele M Franceschini (IBM T.J. Watson Research Center, USA); Anil Krishna (IBM Systems & Technology Group, USA); Robert Montoye (IBM Research Division, USA); Dheeraj Sreedhar (IBM Research Division, India); Augusto Vega (IBM Research Division, USA); Hangu Yeo (IBM, USA); Charles Johnson (IBM Research Division, USA)

Abstract - This paper describes a hardware processor architecture that can achieve the holy grail of SDR: a general-purpose processor that enables high-throughput, low-latency processing for layer 1 through layer 3 for a complete basestation on a chip, while meeting the highest demands of WCDMA and LTE-advanced. The starting point for this architecture is IBM's PowerEN processor, a multicore, massively multithreaded platform that employs general-purpose Power processor cores and includes extensions that address functions appropriate for wired network-edge applications. We consider here a potential evolution of PowerEN to address layer 1 functions, implementing SDR on a general-purpose processor platform for 3G and 4G basestations. Incorporation of a vector-based accelerator (VBA) enables an enhanced PowerEN to support the evolving 3G and 4G standards at a sufficient level of performance for LTE-advanced and beyond, in a fully programmable and scalable fashion. VBA has the appearance of a traditional SIMD unit attached to each general-purpose processor, but includes features that dramatically increase its processing capability for SDR. We provide details of the VBA architecture and describe aspects of programming models for its use.


Implementation of Parallel Lattice Reduction-Aided MIMO Detector Using Graphics Processing Unit (paper) (presentation)
Taehyun Kim (Hanyang University, Korea); Hyunwook Yang (Hanyang University, Korea); Chiyoung Ahn (Hanyang University, Korea); SeungWon Choi (Hanyang University, Korea)

Abstract - Recently, Multiple Input Multiple Output (MIMO) has been emerged as an essential technology for providing a high transmission rate required in next generation mobile communications. Maximum Likelihood (ML) and Zero Forcing (ZF) are the typical methods for designing the MIMO detector. Since H. Yao proposed Lattice Reduction (LR) algorithm for the MIMO detector, one can exploit the diversity gain provided by the LR method of which performance is quite comparable to that of ML algorithm while the complexity is almost as simple as the ZF algorithm. Since the LR algorithm is an iterative method, the LR detector must take a lot of operation time if a serial processor like Digital Signal Processing (DSP) is adopted as the main processor. In this paper, in order to minimize the processing time of the LR-aided detector, Graphics Processing Unit (GPU) has been proposed as the main processor in such a way that the detection can be performed in parallel processing using multiple threads in the GPU. We have implemented an LR MIMO detector using GPU.


Parallel Implementation of Hidden Markov Models for Wireless Applications (paper) (presentation)
Shawn Hymel (Virginia Tech, USA)

Abstract - Hidden Markov Models (HMMs) provide the means to model sequential data that go through a series of states over space or time. HMMs are widely used in speech recognition algorithms and have seen application in wireless communications, including specific emitter identification and signal detection and classification. Unfortunately, the use of HMMs in cognitive radio is hindered by their computational complexity. This paper proposes an extremely fast accelerator using graphics processing units (GPU) that allows for model training and pattern recognition on the fly. Specifically, the Baum-Welch, Forward, and Viterbi algorithms are written to take advantage of the GPU's ability to handle single instruction, multiple data (SIMD) parallelization. The paper shows that the speed benefits from parallelization are maximized when a large number of HMM states are used. While general purpose computing on graphics processing units (GPGPU) is a fairly recent field, the advent of low-power, small profile graphics accelerators for handheld devices opens new doors for parallel processing in the realm of software defined radios.

Session 3B: Receiver Design - Part 2

A Low Complexity Real-time MIMO-preprocessing for Fixed-Complexity Sphere Decoder (paper)
Xuezheng Chu (Queen's University Belfast, United Kingdom); John McAllister (Queen's University Belfast, United Kingdom); Roger Woods (Queens University Belfast, United Kingdom)

Abstract - Modern Multiple-Input Multiple-Output (MIMO) communication systems place huge demands on embedded processing resources in terms of throughput, latency and resource utilization. State-of-the-art MIMO detector algorithms, such as Fixed-Complexity Sphere Decoding (FSD), rely on efficient channel preprocessing involving numerous calculations of the pseudo-inverse of the channel matrix by QR decomposition and ordering. These highly complicated operations can quickly become a real-time bottleneck, exaggerated as the number of antennas in a MIMO detector increases. This paper describes a novel sorted QR decomposition (SQRD) algorithm for FSD in MIMO, which significantly reduces the complexity and latency of this preprocessing step and increases the throughput of MIMO detection. It merges the calculations of the QR decomposition and ordering operations to avoid multiple iterations of QR. Specifically, it shows that SQRD reduces the computational complexity by over 60-70% when compared to conventional MIMO preprocessing algorithms. In 4x4 to 7x7 MIMO cases, the approach suffers merely 0.1-0.2 dB reduction in Bit-Error-Rate (BER) performance.


Tree-Based Adaptive Spatial Detection for Adaptive Modulated MIMO Systems (paper)
Chengwei Zheng (Queen's University Belfast, United Kingdom); Yun Wu (Queen's University Belfast, United Kingdom); John McAllister (Queen's University Belfast, United Kingdom); Roger Woods (Queens University Belfast, United Kingdom)

Abstract - Adaptive Multiple-Input Multiple-Output (MIMO) systems achieve a much higher information rate than conventional fixed schemes due to their ability to adapt their configurations according to the wireless communications environment. However, current adaptive MIMO detection schemes exhibit either low performance (and hence low spectral efficiency) or huge computational complexity. In particular, whilst deterministic Sphere Decoder (SD) detection schemes are well established for static MIMO systems, exhibiting deterministic parallel structure, low computational complexity and quasi-ML detection performance, whilst there are no corresponding adaptive schemes. This paper solves this problem, describing a hybrid tree based adaptive modulation detection scheme. Fixed Complexity Sphere Decoding (FSD) and Real-Values FSD (RFSD) are modified and combined into a hybrid scheme exploited at low and medium SNR to provide the highest possible information rate with quasi-ML Bit Error Rate (BER) performance, while Reduced Complexity RFSD, B-Chase and Decision Feedback (DFE) schemes are exploited in the high SNR regions. This algorithm provides the facility to balance the detection complexity with BER performance with compatible information rate in dynamic, adaptive MIMO communications environments.


Experimental Characterisation of a Large Aperture Array Localisation Technique using an SDR Testbench (paper) (presentation)
Marc Willerton (Imperial College London, United Kingdom); David Christopher Yates (Imperial College London, United Kingdom)

Abstract - In this paper, experimental results detailing the localisation of a signal source implemented on a Software Defined Radio (SDR) testbed using array signal processing methods will be presented. Large aperture array signal processing techniques are used to attempt to locate the position of a signal source operating in the near-far field of the array. Typical application scenarios include an Arrayed Wireless Sensor Network (AWSN) of distributed nodes for example placed on soldiers in a battlefield or wildlife for environmental studies. In a traditional small aperture array system, target localisation is performed assuming the source is present within the far field of the array. This allows the assumption that signals arriving at the array elements are planar providing the basis for the construction of the plane wave manifold vector which is used to model the received array signal. It also provides the assumption that array sensors are all approximately the same distance from the source and hence signals from a given source are all received with equal amplitude.


New PLL for Software Defined Radio, Cognitive Radio, and Dynamic Spectrum Access (presentation not available)
Marc Zuta (Marc Zuta& Co., Israel)

The Phase-Locked Loop PLL greatly affects the performance of modern radio [1], [2]: SDR requires that all the parts of the radio be reconfigurable, to adapt to any standard and Fig. 1 illustrates uses of PLLs in a radio system. The RF unit is presently difficult to control in software; an essential component there, the PLL, did not keep pace with developments in telecom. A new technology uses information available in the PLL synthesizer to greatly improve performance over presently used Integer-N and Fractional-N PLLs. Software Defined Radio can benefit from the flexibility of the Multibit PLL and its improved phase noise, frequency settling speed and frequency resolution.


Polyphase Up Converter Channelizer for Fully Digital Frequency Hopping Modem (paper) (presentation)
frederick j harris (San Diego State Univ, USA); Elettra Venosa (San Diego State University, USA); Xiaofei Chen (San Diego State University, USA)

Spread spectrum techniques have produced results in many important fields like communications, navigation, and test systems. Frequency hopping (FH) is one of the common spread spectrum techniques in which a frequency band, called hopping band, that includes M channels, is accessed by a controlled sequence of frequency shifts over N different center frequencies. In such a system, the modulation process occurs in two steps. At first a signal is baseband modulated, generally by using an analog M-FSK modulator, over one of the M possible center frequencies and then, the hopping band, that contains the M-FSK modulated signal, is hopped over one of the N possible hopping frequencies by a second tier up converter. In spite of the efforts made in the direction of digitizing both the FH modulator and demodulator, today, the frequency hopping system is still implemented in the analog way. No fully digital transceiver exists to perform frequency hopping modulation. In this paper we present a fully digital frequency hopping modulator.

Session 3C: Cognitive Radio and Dynamic Spectrum Access - Part 2

Enhanced Low-Complexity Detector Design for Embedded Cyclostationary Signatures (paper)
Paul D Sutton (Trinity College Dublin, Ireland); Linda Doyle (Trinity College Dublin, Ireland)

Abstract - This paper presents a novel cyclostationary signature detector designed for robust detection of embedded signatures under frequency-selective fading conditions. Cyclostationary signatures are features which may be intentionally embedded in a digital communications signal, detected through cyclostationary analysis and used as a unique identifier. It has been shown that such signatures can also be employed to derive key signal parameters including carrier frequency and bandwidth, making them a powerful tool to support network coordination in dynamic spectrum access scenarios. Signature detection can be compromised under conditions of frequency-selective fading whereby a deep fade can destroy an individual signature. The detector presented in this paper can reduce the destructive effects of such fading conditions, greatly improving detection performance. These improvements are illustrated through simulation results which compare the performance of our detector with that of existing designs. Implementation of the detector design on an existing software radio architecture is examined and a number of key design trade-offs are discussed.


A TVWS ZigBee Prototype (presentation)
James Neel (Cognitive Radio Technologies, LLC, USA)

Abstract - This presentation will review a prototype ZigBee network developed by Cognitive Radio Technologies, LLC (CRT) for operation in the unlicensed TV Bands (TV White Space). The paper will address issues posed by ZigBee operation in the TV White Space (e.g., overlay of a hierarchical channel enabling topology on various ad-hoc data topologies), quantify expected operational benefits (e.g., range and node density), and describe anticipated market applications.


Spectrum Sharing Method using Frequency Priority Table for Reducing Interference among Secondary Systems (paper)
Kazuhisa Okamoto (The University of Elecro-Communications, Japan); Mai Ohta (The University of Electro-Communications, Japan); Kei Inage (The University of Electro-Communications, Japan); Takeo Fujii (The University of Electro-Communications, Japan); Masayuki Ariyoshi (NEC, Japan)

Abstract - By increasing the demand for radio communication applications, the shortage of spectrum resource becomes a serious problem. However, there are lots of unused frequency in the time domain and space domain. Recently, cognitive radio has attracted attention for one of the solution for spectrum resource shortage by utilizing above vacant spectrum, Primary-secondary spectrum sharing system is well known as one of cognitive radio systems. In this system, the secondary users transmit the signals on the same spectrum of the primary users without giving interference from secondary users to the primary users. In current researches for primary-secondary systems, one pair of primary users and that of secondary users are considered to realize spectrum sharing. However, in the future, we have to consider multiple secondary systems with different characteristics are shared on the same spectrum. Therefore, the target of this paper is efficiently sharing the same spectrum among multiple secondary systems.


A Software-Defined Radio Prototyping Platform for Cognitive Radio Applications (paper) (presentation)
Christian Kocks (Universitt Duisburg-Essen, Germany); Alexander Viessmann (Universitt Duisburg-Essen, Germany); Andrey Skrebtsov (Universitt Duisburg-Essen, Germany); Guido Bruck (University of Duisburg Essen, Germany); Peter Jung (Universitt Duisburg-Essen, Germany)

Abstract - During the last decades, the demand for higher data rates in wireless communication systems grew steadily. While the number of communication systems increased significantly, the amount of available spectral resources has remained constant. To exploit spectral resources more efficiently, cognitive radio concepts have become of utmost interest. The goal of cognitive radio systems is to sense the system's immediate environment and react upon its findings. Thereby, non-occupied frequency bands can be identified and used for data transmission. To allow the adaptation of a communication system to the outcomes of the sensing operation, a software-defined radio architecture is advantageous. Systems based on a software-defined radio architecture enable the reconfiguration of software defining the physical as well as the media access control layer. Within this manuscript, a software-defined radio prototyping platform developed by the authors is presented. It is ideally suited for rapid prototyping of wireless communication transceivers with cognitive radio functionality.

Workshop 3D and 4D: Requirements and Opportunities: Government R&D Programs (presentations)

Workshop 3F: Test and Measurement - Part 2

RATE (Radio Automated Test Environment) (presentation not available)
Adem Zumbul (TUBITAK, Turkey)

Abstract - RATE (formerly STS) is a fully automated test tool for testing core framework and waveform implementations against SCA compliancy. It is developped by TUBITAK-BILGEM. In this paper, we will summarize the details of RATE tool and summarize how it is possible to test core framework or waveforms against SCA compliancy.


Software Defined Radio Developments and Verification for Space Environmenton on NASA's Communication Navigation, and Networking Testbed (presentation)
Richard Reinhart (National Aeronautics and Space Administration & Glenn Research Center, USA)

Abstract - NASA is developing an experimental payload with software defined radios to investigate communications, networking, and navigation technologies, operationally in the space environment. Each SDR is compliant to NASA's Space Telecommunications Radio System Architecture, a common software interface description standard for software defined radios. Experiment operations will include in-flight reconfiguration of the SDR waveform functions and payload networking software. The flight system will communicate with NASA's orbiting satellite relay network, the Tracking, Data Relay Satellite System at both S-band and Ka-band and to any Earth-based compatible S-band ground station. The paper will provide an overview of the system and discuss development progress and SDR performance, including lessons learned on preparing an SDR-based system for space flight.


Performance Evaluation of a DVB-T2 Mobile System Using a New Time-Variant FIR-Channel (paper) (presentation)
Jerker Bjorkqvist (Abo Akademi University, Finland); Kristian Nybom (Abo Akademi University, Finland); Jukka Rinne (Tampere University of Technology, Finland); Ali Hazmi (Tampere University of Technology, Finland)

Abstract - The second generation terrestrial digital television standard DVB-T2 was standardized in 2009. When evaluating the overall performance of communication systems, such as DVB-T2, different channel models are used to model different reception scenarios. Commonly used channel models are the AWGN, Rayleigh, Ricean, and TU-6 channel models. However, since each of the models simulate a specific reception scenario, it is difficult to ascertain the realistic overall performance of the system. In this paper, we use time-variant FIR-filtering for modeling the reception conditions in a mobile DVB-T2 system. The FIR-filtering is based on mobile field measurements obtained in Helsinki, Finland, in 2010. We apply FIR-filtering on the measurement results in order to replicate a real time-variant channel model which enables performance evaluation of the DVB-T2 system in a mobile environment. Based on the time-variant FIR-filter channel model, we simulate the performance of the DVB-T2 system, and show that there is a small performance loss when the channel conditions vary in time.

Session 4A: SDR Systems

Software Defined FDD/TDD LTE Implementation on Sandblaster SB3500 (paper)
Vaidyanathan Ramadurai (Optimum Semiconductor Technologies Inc., USA); John Glossner (Optimum Semiconductor Technologies, USA); Gary Nacer (Sandbridge Technologies, USA); Daniel S Iancu (Optimum Semiconductor Technologies & Tampere University of Technology, Tampere, Finland, USA); Saurabh Lahoti (Sandbridge Technologies, USA); Sitij Agrawal (Sandbridge Technologies, USA); Meng Yu (Sandbridge Technologies Inc., USA)

Abstract - In this paper, we present a software implementation of an LTE baseband receiver for both Frequency Division Duplex (FDD) and Time Division Duplex (TDD) system on Sandblaster SB3500 which is based on the Sandblaster 2.0 architecture. The Sandblaster SB3500 is a compact and power efficient System on Chip (SOC) platform designed for wireless and multimedia devices. The SB3500 provides a high degree of parallelism both at the data level and at the instruction level. Additionally, the SB3500 allows simultaneous execution of 12 independent threads thereby allowing real time tasks to run in parallel. The SB3500 also has facility for different types of Direct Memory Access (DMA) like block DMA and scatter/gather DMA. We present a brief overview of the Sandblaster 2.0 architecture followed by introduction to an LTE baseband receiver. In LTE, the downlink multiple access is based on the Orthogonal Frequency Division Multiple Access (OFDMA) and the uplink multiple access is based on the Single Carrier Frequency Division Multiple Access (SCFDMA). We explore some key blocks in an FDD and TDD LTE system, difference in algorithms/implementation followed by thread level and block level optimizations for each system on SB3500 architecture.


Implementation of software-based 2X2 MIMO LTE Base Station System Using GPU (paper) (presentation)
Seunghak Lee (Hanyang University, Korea); Chiyoung Ahn (Hanyang University, Korea); SeungWon Choi (Hanyang University, Korea)

Abstract - In this paper, we demonstrate an implementation of a software-based 2X2 MIMO base station system for LTE mobile communications. The implemented base station system processes baseband signals on a GPU. GPU is a high-speed parallel processor which provides very important advantage of using a very powerful C-based programming environment that is Compute Unified Device Architecture (CUDA). From our experimental tests of video stream data of LTE, we have verified that the GPU-based modem is surely capable of real-time processing of all the baseband signal processing algorithms required for LTE.


Implementation of MPI-based WiMAX Base Station System for SDR (paper) (presentation)
Hyohan Kim (Hanyang University, Korea); Chiyoung Ahn (Hanyang University, Korea); June Kim (Hanyang University, Korea); SeungWon Choi (Hanyang University, Korea)

Abstract - In this paper, we propose a new concept of SDR base station system which adopts a parallel processing technology of clustering environment. We implemented a WiMAX system with SDR technology which adopts the method of Message Passing Interface (MPI) mainly for speed-up operations. In order to maximize the efficiency of parallel processing in signal processing, we analyze how the algorithm at each of modules is related to data to be processed. Through the implemented system, we show a drastic improvement in operation time due to parallel processing using the proposed MPI technology. In addition, we demonstrate a feasibility of SDR system for 4G or even beyond-4G as well.


A low-cost GNSS-R system based on software-defined-radio (paper) (presentation)
Thomas Hobiger (National Institute of Information and Communications Technology, Japan); Jun Amagai (National Institute of Information and Communications Technology, Japan); Masanori Aida (National Institute of Information and Communications Technology, Japan); Hideki Narita (National Institute of Information and Communications Technology, Japan); Tadahiro Gotoh (National Institute of Information and Communications Technology, Japan)

Abstract - On one side Global Navigation Satellite System (GNSS) users try to avoid multi-path signals, i.e. reflections which propagate into the geodetic antenna, as this effect can bias the results. On the other side, the remote sensing community has an increasing interest in analyzing such reflections as they provide valuable information about the physical characteristics of the reflection area. This technology is called GNSS- Reflection (GNSS-R) and operates usually with two antennas in order to monitor direct and reflected signals. One up-looking (RCHP) and one down-looking (LHCP) antenna is deployed at the same site and analysis of the differential delay and/or the cross-correlation function w.r.t. to delay and Doppler shift allows to deduce the physical properties of the scattering surface. In order to develop a GNSS-R off-the-shelf system RHCP and LHCP L1 active patch antennas are utilized together for this purpose. Instead of equipping the antennas with GNSS receivers, signals are sampled directly in the RF and sent to a PC over a Gigabit ethernet connection.


A Many-Core Software Defined Solution for Development and Deployment of Wireless Systems (presentation)
John Irza (Coherent Logix, USA)

Abstract - Increasingly complex wireless systems require design solutions that enable rapid exploration of algorithms, system architectures, and actual over-the-air performance. Recent connectivity between low cost SDR platforms (the USRP family of radios) and popular design environments (MATLAB and Simulink) have enabled a radio-in-the-loop design and verification capability. This approach is ideal for experimentation and prototyping but does not address target deployment on non-USRP platforms. By employing a software defined solution which is used for product deployment as well as serving as a hardware accelerator for design simulation and verification, a true integrated design and deployment environment capability is realized. This enables a simpler, single design flow, unlike traditional multi-tool flows. By eliminating the need to re-target from prototype to production hardware, the engineer benefits by: having more time to fully explore design options and verify compute-intensive "corner cases"; by reusing their development software stack "as-is" in the final deployed product; meeting the constraints of schedule and budget.

Session 4B: Receiver Design - Part 3

Virtex-7 FPGAs Target Software Radio Applications (presentation)
Rodger Hosking (Pentek, USA)

Abstract - The latest Xilinx Virtex-7 FPGA technology offers unprecedented signal processing horsepower for software defined radio applications. These devices deliver twice the resources and 50% lower power consumption compared to previous generation FPGAs, opening up new markets and opportunities. This paper presents compelling design strategies for Virtex-7 FPGAs to optimize high-performance computing solutions for signal acquisition and generation, digital signal processing, and high-speed interconnects. System examples address specific requirements of commercial and defense applications for software radio and radar. Unique modular approaches to board and system-level architectures utilizing these FPGAs will be discussed.


Resource Management Strategies for SDR Clouds (paper) (presentation)
Vuk Marojevic (Polytechnic University of Catalonia, Spain); Ismael Gomez (Polytechnical University of Catalonia & UPC, Spain); Pere Gilabert (UPC, Spain); Antoni Gelonch (Polytechnic University of Catalonia, Spain)

Abstract - Today's base stations are equipped with a set of heterogeneous processing devices, including application-specific integrated circuits (ASICs), general-purpose processors (GPPs), digital signal processors (DSPs), and field-programmable gate arrays (FPGA). Each device typically executes the set of tasks specified at design time. The ongoing advances in radio engineering and digital signal processing, however, suggest the deployment of processor arrays and automatic resource allocation schemes that can allocate the required computing capacity on demand. The approach of considering a data center as the computing core of a base station is then a natural evolution of wireless communications. The digitalization of wireless communications and emerging SDR frameworks facilitates the reconfiguration of radio equipment. The major advantages for mobile terminals would be the possibility of dynamic service and RAT adjustments as a function of environmental conditions and user preferences. Future SDR base stations will be correspondingly reconfigured, but on a much larger scale.


Improving robustness, throughput, latency and channel awareness in a software defined radio (presentation)
Leigh Chang (Redline, USA)

Abstract - Automatic Retry reQuest (ARQ) mechanisms are known to improve the wireless packet error rate (PER) and the link robustness but they are associated with increased latency and decreased throughput. The presentation describes an ARQ mechanism that, when combined with proper channel coding, provides better robustness, throughput and latency and at the same time improves the system awareness of the channel quality. The combination of the ARQ mechanism and channel coding is particularly friendly for software defied radio.

Session 4C: Cognitive Radio and Dynamic Spectrum Access - Part 3

Electromagnetic Spectrum Dominance - An Autonomous and Efficient Spectrum Management System (paper) (presentation)
Syed Shah (DOD/DDR&E/RD, USA); Joseph Molnar (Naval Research Laboratory, USA); Raymond Cole (Naval Research Laboratory, USA); Trang Mai (Naval Research Laboratory, USA)

Abstract - Modern warfare is not just about air, sea, and land dominance, it is also about electromagnetic spectrum dominance. Spectrum dominance is the ability to control how the Electromagnetic Spectrum (EMS) is utilized. This implies the ability for the military to conduct an operation and be able to allow or deny, exploit, deceive, disrupt, degrade, and/or destroy adversary's ability to use the EMS, while preserving their own ability to use the EMS as mission and policy dictates with minimal disruption to civilian use. Spectrum dominance is often a pre-requisite for information dominance, which is key to the success of any military operation. Spectrum, however, is a finite resource and its use must be effectively and efficiently managed to ensure military superiority and readiness. It is challenging to have adequate spectrum management in place to achieve spectrum dominance. This paper discusses the need of an agile and efficient spectrum management system to achieve spectrum dominance in military operation.


A Radio Architecture Compliant with the ECMA-392 Standard for Personal White Space Devices (presentation not available)
Vivek Sriram Yenamandra Guruvenkata (Analog VLSI Lab & Ohio State University, USA); Mohammed Ismail (Ohio State University, USA)

Abstract - Wireless devices which operate in the TV-white spaces, unused regions of the frequency spectrum, have recently gained much attention. These devices find a variety of applications such as in wireless rural broadband access which has attracted interest from developers worldwide. The FCC and other commissions worldwide defined specifications for devices which operate in these frequency bands. These specifications emphasize minimum interference with incumbent signals. This paper focuses on the baseband part of such white space devices, specifically the ADC and DAC architectures, and propose tentative block level specifications for baseband blocks in both the receive and transmit chains making them suitable for low power full system-on-chip integration in bulk CMOS. Coupled with our own recently derived RF front end specifications, the proposed overall radio transceiver architecture meets the ECMA-392 specification, one of the first standards published worldwide which specifies a medium access control (MAC) layer and a physical layer for personal/portable white space devices.


Model-Based Spectrum Management (presentation)
John A. Stine (The MITRE Corportation, USA)

Abstract - Spectrum management has been a challenging task for tactical environments. Many opportunities to reuse spectrum spatially and temporally are lost due to a lack of agility in spectrum management approaches. The promise of dynamic spectrum access (DSA) technology is constrained by the overarching policy of doing no harm to existing systems and so management of these technologies is no different than the management of other radios. Model- based spectrum management (MBSM) provides an alternative method to build a spectrum management system that provides dynamic spectrum management and enables dynamic spectrum access. MBSM builds spectrum management on top of a spectrum consumption modeling approach. All types of uses of spectrum are modeled using the spectrum modeling approach and then generic algorithms are used to assess the compatibility of these models and so the compatibility of spectrum uses. Spectrum consumption modeling serves as loose coupler that allows spectrum management systems to interoperate and provides a standard way to create and convey spectrum authorizations to RF systems and policy to DSA systems that is machine readable. This presentation will describe how models are built and how using models would support the agile management described.

Tutorial 4F: 700 MHz Nationwide Public Safety Broadband Network (presentation)
Fanny Mlinarsky (octoScope, Inc.)

Exhibition and Technology Showcase

Rapid FPGA Assembly for GNURadio
Richard Stroop (Virginia Tech & Configurable Computing Laboratory, USA); Peter Athanas (Virginia Tech, USA)

Abstract - Software defined radios have changed the paradigm of slowly designing custom radios, instead allowing designers to quickly iterate designs with a large range of functionality. With the help of environments like GNURadio, a designer can prototype radios with greatly improved productivity. Unfortunately, the playing field is limited by software performance, and there is no way to achieve the range of radio designs possible with actual physical radio hardware. In order for SDRs to become more prevalent in radio prototyping and development, accelerators must be added to speed up the digital signal processing of high-throughput and/or computationally intensive portions. Custom DSPs, GPUs, FPGAs and more and more GPPs have all been added to SDRs to try and speed them up. One difficulty in this is that by adding these accelerators, the "instant gratification" dynamic of the GNURadio is lost. In this paper, an enhanced GNURadio flow is presented that seamlessly augments the GNURadio software-only model with FPGAs, yet preserves the GNURadio dynamics by providing full-custom radio hardware/software structures in seconds.


MIMO/OTA (Over the Air) Controlled Environment Testing
Fanny Mlinarsky (octoScope, USA)

Abstract - Wireless industry is migrating from conducted to over the air (OTA) testing. Modern wireless handsets and smart phones with cellular, 3G/4G, Wi-Fi, Bluetooth and GPS radios cry out for OTA test methods due to a sheer number of connections. Conducted coupling whereby antennas are replaced with cabling is unsuitable for MIMO and beamforming technologies where antennas may be a significant factor influencing device performance. In this demo we will review OTA test methods and metrics being developed at 3GPP and CTIA and will discuss practical approaches to fast and accurate OTA based production testing.


Airblue: A Reconfigurable Wireless Transceiver
Kermin Fleming, Jr (MIT, USA); Arvind (Massachusetts Institute of Technology, USA); Alfred Man Cheuk Ng (Qualcomm Inc, USA); Hari Balakrishnan (Massachusetts Institute of Technology, USA)

Abstract - Over the past few years, researchers have developed many cross-layer wireless protocols to improve the performance of wireless networks. Experimental evaluations of these protocols have been carried out mostly using software-defined radios, which are typically two to three orders of magnitude slower than commodity hardware. FPGA-based platforms provide much better speeds but are quite difficult to modify because of the way high-speed designs are typically implemented. We have developed Airblue, an FPGA-based software radio platform, that is both easy to modify and runs at speeds comparable to commodity hadware and have used it to perform several cross-layer experiments. Airblue is built on top of commercially available components, with a total cost of less than $2500 per transceiver.


A Novel Three-Level Hierarchical Algorithm for UL Scheduling in Mobile WiMAX
Ihsan M Shahwan (CCNY, USA)

Abstract - Scheduling algorithms that ensure efficient radio resource allocation and reliable QoS delivery are of utmost importance in WiMAX systems. This paper presents and devises a three-level hierarchical algorithm for UL scheduling in OFDMA-based Mobile WiMAX systems. The algorithm utilizes an opportunistic cross-layer approach in conjunction with admission control and policing mechanisms in order to meet QoS requirements for different classes of services while maximizing the overall system throughput. The performance of the proposed UL scheduling algorithm is compared with that of a typical two-level hierarchical scheduling algorithm that utilizes strict priority at the first level of the hierarchy.


Rapid SCA Development for the DSP (Demonstration Proposal)
Andrew Foster (PrismTech Limited, United Kingdom)

Abstract - One of the features of evolving SCA Next standard will be the enhanced support for hosting SCA components on specialized processing environments such as DSPs and FPGAs. There are several tools on the market that support the rapid development of SCA resources for the GPP by generating SCA compliant C++ source code. Spectra CX is the first SCA IDE to offer rapid development of SCA resources for the DSP by compiling the design of an SCA resource into optimized C code utilizing a SCA Next compliant lightweight CORBA implementation. This demonstration will show how new features in Spectra CX enable the rapid design, implementation and deployment of an SCA resource targeting TI DSPs. The demonstration will include an SCA assembly where resources executing on the GPP communicate with and send data to the resources executing on the DSP.


SDR Receiver For Amateur Satellites and CUBESAT Ground Station
Carl B. Dietrich (Virginia Tech & Wireless @ Virginia Tech, USA)

Abstract - We propose to demonstrate a Software-Defined Radio (SDR) satellite ground station for the reception of signals from low-earth orbit Cubesats using the Amateur Radio frequencies. This receiver is designed to replace the Commercial Off the Shelf (COTS) radios that are typically used in satellite ground stations. In this document we briefly discuss the construction of the station and the planned demonstration.

Session 5A: RF, IF, and ADC - Part 1

Practical Use of Reconfigurable Radios in Air Combat Training Systems (paper) (presentation)
Joseph Testa (DRS Training & Control Systems, USA)

Abstract - This paper reviews and analyzes the collaborative efforts of DRS TCS, DRS Signal Solutions, and SCA Technica to transition a legacy data link to a modern Software Defined Radio (SDR) that will provide interoperability with fielded legacy data links while providing "reconfigurability" to support new more advanced waveforms. Several efforts are described including: Extracting the legacy air combat training data link waveform from a hardware based data link product. Modeling the waveform for rapid prototyping on an SDR platform and porting the waveform to an appropriate target radio. Identifying a target SDR radio that will support the SCA, the modeled waveform, and provide the HW infrastructure to support future JTRS airborne networking waveforms planned for air combat training. The paper will summarize the development challenges and resulting innovations experienced during the development and planned fielding of a backward compatible radio that is reconfigurable to support a future JTRS air combat training waveform.


A Tunable Wideband RF Front-End for SDR (paper)
Michael Benonis (Virginia Polytechnic Institute and State University, USA); Sm Hasan (GE Global Research, USA); Randall Nealy (Virginia Tech, USA); Jeffrey Reed (Virginia Tech, USA)

Abstract - In the modern age of radio frequency integrated circuits (RFICs), it is now possible to build a radio transceiver capable of operating over more than a decade of carrier frequencies. Unfortunately, RFICs by themselves are not enough to form a full radio transceiver. They must be coupled with filters, a power amplifier, and a duplexer to be useful in real-world situations. In this paper, we report on work that we have done on designing and testing a front-end containing these elements. The major contribution of this paper is the use a fully-tunable pre-selection filter instead of fixed-frequency filters. Filters are the most important part of any radio transceiver design. In order to maximize sensitivity at a particular frequency, it is necessary to limit the amount of noise and undesired energy that is coupled into the transceiver. In traditional superheterodyne architectures, this is achieved by using a fixed pre-selection filter prior to the low-noise amplifier to reduce distortion.


Single-Configurable Chip Solution for Digital-Front End with Supporting Multiple Standards of Wireless Communications and Broadcasting (presentation not available)
Fa-Long Luo (IEEE, USA); Ward Williams (Element CXI, USA)

Abstract - With the rapid development and world-wide deployment of broadband wireless communication and digital broadcasting infrastructures, the use of digital processing technology in the front-end and radio frequency unit is explosively increased. Unlike baseband processing, front-end is tightly connected to radio frequency layer and hence imposes great limitations and difficulties on digital processing speed, memory, computational capability, power, size, data interfaces and bandwidths. There have been three representative camps to provide the digital front-end solution. One is ASIC based solution which is excellent in power consumption and performance but is impossible to support multiple standards and multiple applications with a single chip. Also, the ASIC based solution is not suitable for upgrading better signal processing algorithms which highly determine the performance of digital front-end systems. The second is FPGA or DSP based solution which offers great flexibilities in supporting multiple standards/models/applications and also in supporting different signal processing algorithms.


Circular Multiuser Beam-Free Active Phased Array and Comparison with the Standard Multisector Antennas for Mobile Communication (presentation not available)
Igor Sergeev (IZMIRAN & GEOSCAN International Agency, Russia)

Abstract - A multiuser beam-free cylindrical adaptive active array is considered. Such antennas can be used instead of standard multisector antennas and multibeam phased arrays. The multiuser beam-free method implies that coverage area is not divided into cells with different frequencies. Instead, all the users can use all the frequencies and the active array selects signals by their position. The comparison of the standard multisector antennas with the beam-free array consisting of the same number of elements shows that the capacity (number of users operating on the same frequency) increases up to 2 times as against 6-sector antenna and 3 times as against 3-sector. Also the beam-free antenna is easily flexible. To increase the capacity it is just sufficient to add antenna elements without construction changing.

Session 5B: Advanced Signal Processing - Part 1

Tracking Performance of the MMax Conjugate Gradient Algorithm (paper) (presentation)
Bei Xie (Virginia Tech, USA); Tamal Bose (Virginia Tech, USA)

Abstract - Partial update (PU) conjugate gradient (CG) algorithms have been developed to reduce the computational complexity of the full-update CG. Among the basic partial update methods, the MMax CG can achieve comparable convergence performance and steady-state mean-square-error (MSE) performance as the full-update CG in a time-invariant system while significantly reducing the computational complexity. In this paper, the tracking performance of the MMax CG for a time-variant system is studied. Theoretical analyses and simulation results of the convergence and steady-state performance are presented. The performance of the MMax CG is also compared with the MMax recursive least squares (RLS) algorithm. Computer simulations are presented to support the theoretical analyses.


Combined Multiuser Signal Classification and Blind Equalization (paper)
Barathram. Ramkumar (Virginia Tech, USA); Tamal Bose (Virginia Tech, USA)

Abstract - A Multiuser Automatic Modulation Classifier (MAMC) is an important signal processing component of a multi-antenna cognitive radio (CR) receiver that can identify the modulation format employed by multiple users simultaneously. In a typical wireless communication system, transmitted signals are subjected to multipath fading and interference from other users. Multipath fading not only affects symbol detection performance but also affects the performance of the automatic modulation classifier (AMC). A multi-input multi-output (MIMO) blind equalizer is another important component of a multi-antenna CR receiver that improves symbol detection performance by reducing inter symbol interference (ISI) and inter user interference (IUI). In a CR scenario it is preferable to consider the performance of the AMC also while adapting the parameters of the blind equalizer. A cyclic cumulant (CC) based MAMC was recently proposed by the authors. In this paper, we propose a MIMO blind equalizer that improves the performance of both multiuser symbol detection and CC based MAMC. Computer simulations are provided to illustrate this concept and the proposed algorithm.


Experimental Evaluation of Interference Avoidance Opportunistic Secondary Transmission for Coexistence with Primary Systems (paper)
Srinivas Pinagapany (Rutgers University, USA); Samson Sequeira (Rutgers University & WINLAB, Rutgers University, USA); Abhishek Bindiganavile (Rutgers University, USA); Yasunori Futatsugi (NEC Corporation, Japan); Masayuki Ariyoshi (NEC, Japan); Predrag Spasojevic (Rutgers University, USA)

Abstract - Traditional spectrum licenses have static and exclusive rights to a fixed amount of spectrum. With the proliferation of wireless broadband services, the spectrum scarcity problem has today become one of national importance in countries facing this crisis. The concept of dynamic spectrum access (DSA) in which an unlicensed device opportunistically accesses the spectrum in the licensed frequency bands can help alleviate this problem. The licensed devices are called the primary users (PU) of the band where as the unlicensed devices are called the secondary users (SU). However, this approach requires that the incumbent PU be protected from detrimental interference from the opportunistic SU. A parallel problem in this scenario is that the SU must also be assured of some quality of service while having to overcome the interference from the PU(s). Key functions to enable DSA contain spectrum sensing and interference avoidance transmission. The former is to find the opportunity for secondary use of the spectrum; and the latter is for SU to coexist with PU.


Reducing Observation Time for Reliable Cyclostationarity Feature Extraction (paper) (presentation)
Amy Malady (DSPRL - [email protected], USA); A. A. (Louis) Beex (DSPRL - [email protected] & Virginia Tech, USA)

Abstract - Cyclostationarity is a promising feature for signal classification and detection as extracting cyclostationarity features can be done with minimal pre-processing tasks - tasks that often require a priori knowledge of channel characteristics and signal parameters that are unavailable during detection and classification stages. For some applications of interest, the most restrictive requirement for using cyclostationarity features is the long observation time required for reliable classification and detection. The objective of this work, in particular, is to improve the practicality of using cyclostationarity feature-based detection and classification by reducing observation time requirements through the use of robust statistics. The incorporation of robust statistics has been successful in reducing SNR requirements for cyclostationarity feature extraction and in improving QPSK symbol timing estimates when SNR is greater than or equal to 0 dB.


Interference Tolerable Threshold Analysis in Cognitive Femtocells (paper) (presentation)
Atsushi Nakata (NEC Corporation, Japan); Kamran Arshad (University of Surrey, United Kingdom); Klaus Moessner (University of Surrey, United Kingdom)

Abstract - In this paper interference management in co-channel deployment of macrocell and cognitive femtocells is investigated. For the purpose of the aggregate interference mitigation from all femtocell access points (FAP) to macrocell user equipment (MUE) and the purpose to increase the radio link quality of femtocell system, a parameter named interference tolerable threshold (Ith) is introduced, the aim is to reduce the interference an individual FAP causes to MUE to a level lower than Ith. A dynamic Ith control scheme is proposed to determine the appropriate value of this threshold. The simulation results show that the highest available Ith depends on the total number of FAPs, a larger number of FAPs does affect aggregate interference even if the individual interference is in acceptable range. The proposed method, however, achieves the adaptation of the highest available Ith without needing knowledge about the number of FAPs in the vicinity of MUEs.

Session 5C: Compilers, Software, and Tools - Part 1

On the use of an Algebraic Language Interface for Waveform Definition (paper) (presentation)
Michael L Dickens (University of Notre Dame, USA); J. Nicholas Laneman (University of Notre Dame, USA)

Abstract - We discuss implementation aspects of a software-defined radio system that allows the user to define waveforms using an algebraic language interface, currently as an extension to C++. Current software-defined radio systems provide waveform definitions through a combination of a graphical interface, markup language, interpreted script, and compiled code. No matter which methods are used, the actual executed code generates each waveform via a series of graph-style connections: instantiating blocks and then explicitly connecting ports between blocks. We propose a system that allows the user to define waveforms using a text-based algebraic language interface similar to that found in the MathWorks' MATLAB or GNU Octave. Our system simplifies the waveform programming abstraction by using implicit graph-style connections; it makes extensive use of C++ templates and operator overloading to allow this high-level abstraction. Example code is provided for comparison and contrast of different methods of waveform definition.


Using a graphical interface for Fast FPGA design revision in a hierarchical structure for software-defined communications applications (paper) (presentation)
Frank Raffaeli (National Instruments, USA)

Abstract - Achieving fast-turnaround on revision cycles is important both for research and for deployment SDR platforms. Modern large FPGAs often have prohibitively long compile times, extending for several hours. Often, the learning cycle in academic applications is curtailed by the constraint of the compile operation. Using pre-compiled DSP "megablocks" within the LabView FPGA module, a hierarchical design can be deployed from the simulation phase in a matter of seconds instead of hours. The mega-block is a generic DSP engine that utilizes both a combinatorial and a sequential framework to combine the DSP blocks within the FPGA's infrastructure to build a re-configurable function. The megablocks are physically configured using a combination of muxes and scripted commands. From the user's point of view, a function(s) can be written and simulated in the graphical language, LabView, then deployed to the megablocks within a few seconds.


Army Policy-based Automation Tools (presentation not available)
Salvador Ditri (Shared Spectrum Company, USA); Filip Perich (Shared Spectrum Company, USA); Gregory Rucker (US Army, USA); Mark Saltzman (Army, USA)

Abstract - Shared Spectrum Company (SSC) in collaboration with the US Army Communications-Electronics Research, Development and Engineering Center (CERDEC) Space & Terrestrial Communications Directorate (S&TCD) has developed a suite of radio device Policy Automation Creation & Simulation (PACS) tools capable of enforcing multi-source policies and computing configuration opportunities based on the current environment. PACS relies on declarative spectrum access control rules so that policies only specify rules that a DSA-enabled device must meet before it can transmit. The policies may consider the radio's capability (e.g. ability to sense, report its location, its transmission frequency range, etc.), state (e.g. current transmission power, modulation, antenna direction, etc.), location, time, and spectral environment (i.e. local signal detector results, information from other radios, etc.) for allowing or denying a transmission. The core feature of the policy engine is the ability to evaluate policy rules expressed in the W3C Web Ontology Language (OWL) and W3C Semantic Web Rule Language (SWRL).


Analysing schedulability of SDR systems based on cyclostationary extension of periodic tasks (paper)
Jan Westmeijer (MIMOON, Germany); David Guevorkian (Tampere University of Technology, Finland)

Abstract - An important problem in designing SDR systems is to obtain a minimal HW requirements to support implementation of desired set of radios. This problem can be solved by a method that would find out whether a valid schedule exists to perform, before predefined deadlines, all the tasks (algorithms) of a set of radios on given set of HW components. It is known that radios are periodic in nature (i.e. algorithms are periodically repeated). Therefore, to analyse schedulability of a single radio it is enough to consider only one period of the radio. However, since an SDR system must support several radios, larger period of time that includes several full periods of each radio must be analysed. In this work, a method for analysing availability of a schedule to perform given set of radios on a HW platform is proposed based on cyclostationary extension of radio tasks. A necessary condition for existence of a schedule is derived. This allows to find minimum HW requirements to support a desired set of radios.

Workshop 5D: Requirements and Opportunities: How to Win SBIR Phase 1, 2 and 3 (presentations)

Workshops 5E and 6E: The Future of Whitespace Communications (presentations)

Tutorial 5F: Cyber Warfare in a Wireless World (presentation)
LT D.A. Brown, CDR T.O. Walker, Ph.D., C. R. Anderson, Ph.D. (United States Naval Academy)

Session 6A: RF, IF, and ADC - Part 2

Cascade Linear Phase Recursive Half-Band Filters Implement the Most Efficient Digital Down-Converter (paper)
frederick j harris (San Diego State Univ, USA)

Abstract - The digital down converter (DDC) is a fundamental component in modern receivers. Two different architectures, operating on very different principles, have become dominant in modern receiver systems. The first of these is the Edwin Armstrong heterodyne model formed by three processes, a quadrature heterodyne, a low-pass filter, and an M-to-1 down sampler. The second is the band centered polyphase filter in which the three processes are performed in the reverse order, an M-to-1 aliasing down sampler, an M-path partitioned low-pass filter, and an M-point complex phase-alignment vector. The second option finds great favor in multichannel receivers in which multiple narrowband signals are separated by the sin-gle filter coupled to an IFFT that provides the multiple M-point phase alignment vectors. In this paper we present a polyphase filter form of the single channel DDC that offers significant computational advantages over the conventional single channel DDC. This architecture may present the minimum power implementation of a DDC and likely will find great value in battery operated radio receivers.


An Efficient Full Digital Frequency Hopping Demodulator based On Polyphase Filter Banks (paper) (presentation)
frederick j harris (San Diego State Univ, USA); Xiaofei Chen (San Diego State University, USA); Elettra Venosa (San Diego State University, USA)

Abstract - Frequency-hopping spread spectrum (FHSS) is a method of transmitting radio signals by rapidly switching a carrier among many frequency channels, using a pseudorandom sequence known to both transmitter and receiver. There are a number of advantages of using FHSS system, such as resistant to narrow band interference, difficult to intercept, and spectrum sharing with many types of existing transmissions. The demodulation of a FHSS signal can generally be partitioned into two steps. The first step is to de-hop the pseudorandom hopping sequence. The second step is to demodulate the underlying frequency shift keyed (FSK) signal. The conventional frequency hopping modem implements the first step by using analog mixers to down-convert the modulated FSK signal to the intermediate or baseband filter(s), and then uses an analog or a digital FSK demodulator to extract the received information. The reason for using analog mixers in the first step is to avoid processing signals at the very high sample rate that would be required to satisfy the Nyquist criteria for the spectral span of hopping frequencies. As a consequence, the conventional FHSS receivers suffer from analog artifacts which affect the system performance as well as limit flexibility to implement innovative signal options.


Reconfigurable Continuous-Time Delta-Sigma Analog-to-Digital Converters for Software-Defined and Multi-standard Radios (paper)
Vishal Saxena (Boise State University, USA); Sakkarapani Balagopal (Boise State University, USA); Hao Chen (Boise State University, USA)

Abstract - Emerging wireless standards are continuously providing higher data rate and increased amount of flexibility. The recent trend in modern wireless transceivers is towards multi-standard radio solutions that can support a varied range of wireless voice and data transfer services, and Software Defined Radios (SDR). In order to support multi-mode radio operation and switching between standards, reconfigurable hardware architectures have become essential. Moreover, the transceivers should be energy scalable so maximize battery life of the the hand-held radios. This necessitates analog-to-digital converters (ADCs) with reconfigurable bandwidth from 200 kHz up to 160 MHz and with up to 14-bits of resolution. Continuous-time delta-sigma (CT-\Delta\Sigma ) ADCs have recently been explored for wideband data conversion in wireless receivers due to much lower power consumption and inherent anti-alias filtering (AAF). Also, Delta-Sigma ADCs scale well with CMOS technology as they predominantly employ digital circuitry for achieving high dynamic range.


RF Sampling Software Defined Radio for HF Band (paper) (presentation)
Satoru Yokono (Japan Radio Company Co. Ltd., Japan); Takahide Sakasai (Japan Radio Company Co. Ltd., Japan)

Abstract - We propose a 1 - 30 MHz software defined radio (SDR) with high-speed (100MHz) RF sampling. This receiver has a very high sensitivity (8dB NF), IP3 (+23dBm) and 130dB blocking Dynamic range (150Hz BW) This SDR has 2 receiving channels for wideband (1.25MHz to 10MHz) and narrowband (150Hz to 500kHz) . There are no analog mixers, synthesizers and no analog AGC circuit on this receiver. We propose an appropriate NF calculation in the digital section in order to achieve very high sensitivity. We also propose a very high performance analog front-end in order to keep very high IP3 and IP2. Thereby, this SDR has been able to achieve high performance reception with narrowband filtering from 150 Hz to 500 KHz at an oversampled rate of 100 MHz. This SDR also supports various demodulation types, such as DSB, USB, LSB, ISB, CW and Narrow FM.


An Analysis of Active Interference Cancellation for Wideband OFDM System from Multi-band OFDM System (paper)
Keisuke Sodeyama (Yokohama National University, Japan)

Abstract - Recently, the shortage of assignable radio spectrum became a serious issue because of the coexistence of many licensed wireless communications systems. Therefore, cognitive radio technology has gained much attention around the world, which may be aware of its environment and makes occupancy of radio spectrum more efficient. This paper examines numerical results of active interference cancellation (AIC) between wideband OFDM (WB-OFDM) system and multi-band OFDM (MB-OFDM). Since MB-OFDM systems share frequency spectrum with many WB-OFDM systems, and need to coexist with other ultra wideband (UWB) communications systems. The performance of avoidance the interference for WB-OFDM system in MB-OFDM system transmitter. Moreover, computer simulations have been performed to confirm these analytical results.

Session 6B: Advanced Signal Processing - Part 2

Adaptative Antenna Array to Improve Cognitive Radio Performance (presentation not available)
Jos Everardo Ferreira (University of Campinas - UNICAMP, Brazil)

Abstract - The utilization of cognitive radio technology appears as a very useful solution to the efficient use of radiofrequencies, although lots of challenging has been detected to get electromagnetic compatibility among primary (licensed) and secondary (no licensed) users. Considering the diversity of spectrum primary users in terms of locations, antennas directivities and all kinds of telecommunication services, this paper introduces a concept of adaptative irradiating system coupled to the cognitive radio, in order to increasing the signal noise relation in a selective way. It was developed by dividing the spectrum sensing process into antenna sectors and using an automatic selection to tune the radio channel between the transceivers that compose the cognitive link. The performance of this method is compared with conventional radio cognitive system to show some advantages conquered.


An Efficient GPU-based LDPC Decoder for Long Codewords (paper) (presentation)
Stefan Gronroos (Abo Akademi University, Finland); Kristian Nybom (bo Akademi University, Finland); Jerker Bjorkqvist (Abo Akademi University, Finland)

Abstract - The DVB-S2 and DVB-T2 standards for digital television broadcasting specify the use of Low-Density Parity-Check (LDPC) codes with codeword lengths of up to 64800 bits. The real-time decoding of these codes on general purpose computing hardware is interesting for completely software defined receivers, as well as for testing and simulation purposes. Modern graphics processing units (GPUs) are capable of massively parallel computation, and can, given carefully designed algorithms, outperform general purpose CPUs by an order of magnitude or more. The main problem in decoding LDPC codes on GPU hardware is that LDPC decoding generates many irregular memory accesses, which tend to carry heavy performance penalties on GPUs. The high memory access latencies can be partially avoided by decoding several codewords in parallel, as well as by using appropriate data structures to efficiently parallelize memory accesses. In this paper we present the algorithms and data structures used to make log-domain decoding of the long LDPC codes specified by the DVB-T2 standard - at the high data rates required for television broadcasting - possible on a modern GPU.


Simulcast Systems for Public Safety (presentation)
Richard Taylor (Harris Corporation, USA)

Abstract - Simulcast techniques are often used for public safety communications systems to provide RF coverage of densely populated areas where available frequencies are scarce. These systems usually consist of several base station sites with antenna towers, separated by a few miles, with each site transmitting on the same frequency at about the same time. This presentation discusses the unique design issues associated with these types of systems, including managing the cochannel interference in areas where the transmitted signals overlap, and techniques such as linear modulations to mitigate these issues.


Improving MIMO Sphere Detection Through Antenna Detection Order Scheduling (paper) (presentation)
Michael Wu (Rice University, USA); Chris Dick (Xilinx, USA); Yang Sun (Rice University, USA); Joseph R. Cavallaro (Rice University, USA)

Abstract - Multiple-Input Multiple-Output (MIMO) processing is a key technology in broadband wireless technologies such as 3G LTE, WiMAX, and 802.11n. A maximum likelihood (ML) MIMO detector, combined with a soft-input soft-output channel decoder such as Turbo decoder, is used to maximize receiver performance. As an ML MIMO detector is an exhaustive tree-search, a greedy list sphere detection algorithm such as Flexsphere is used to reduce the cost of a hardware realization. However, the list size is reduced. As a result, Flexsphere can not determine the bit-level reliability information, the log likelihood ratio (LLR), of some received bits. One unique property of Flexsphere is that the LLRs of the first layer of the sphere detection do not need to be clipped. We propose a novel modified list sphere detector which leverages this property of Flexsphere. By scheduling a given Flexsphere detector multiple times, where the detector detects the transmit stream in a different permuted order each time, the detector can avoid LLR clipping. Through simulation, we show that this detector improves performance with a moderate increase in complexity compared with other list sphere detectors.


Spread Spectrum Channel Sounder Implementation with USRP platforms (paper) (presentation)
Adrien Le Naour (SUPELEC, France); Olivier Goubet (SUPELEC, France); Christophe Moy (SUPELEC/IETR, France); Pierre Leray (IETR/Supelec Campus de Rennes, France)

Abstract - This paper shows results of a student project on the implementation of a spread spectrum channel sounder using USRP platforms and GNU Radio environment. Such an implementation would have required months of development (ASIC and board design and manufacturing, RF design, etc.) 15 years ago. A few weeks of part time work for 2 students were only necessary here thanks to a software defined radio context. It is planned that this channel sounder could be used in a future cognitive radio context for environment awareness. Context This paper shows the results obtained by 2 students during a project of 6 weeks on the implementation of a channel sounding system on a USRP platform and the GNU Radio development environment. The channel sounding is performed using a direct sequence spread spectrum approach with matched filter at the reception side. This channel sounder could be used for several purposes in the sense of channel effects mitigation.

Session 6C: Compilers, Software and Tools - Part 2

Predictive scheduling of job combinations in SDR systems (paper) (presentation)
David Guevorkian (Tampere University of Technology, Finland); Jan Westmeijer (MIMOON, Germany)

Abstract - In SDR systems, different combinations of radios each consisting of a number of algorithms and having strict timing constraints must be implemented on top of a shared computational platform that typically consists of several types of processors and HW accelerators. To handle such complicated system, efficient scheduler design policies are needed. In this work, we propose an approach to timing policy of SDR schedule creation where we suggest to create or adjust schedules during each established stationary state of the system (when it implements a fixed combination of radios) for all possible states that may occur after the current state. Effectively, this means that possibly static, highly optimized schedules are designed dynamically for the sequence of stochastically changing static job combinations. This way, advantages of the static and dynamic scheduling policies are combined. The proposed method can be applied to scheduler design for any “piece-wise stationary” application where relatively small number of stationary jobs must be supported but the sequence of job combinations is unpredictable. Therefore, the system is stationary for a period of time when combination of jobs is fixed but is non-stationary during larger time periods when job combinations may stochastically change.


Bridging the Gap Between the Cognitive Engine and the SDR (paper) (presentation)
Jakub Moskal (VIStology, Inc., USA); Mieczyslaw Kokar (Northeastern University, USA); Shujun Rachel Li (Northeastern University, USA)

Abstract - Regardless of the type of an inference engine that a Cognitive Radio (CR) employs, each CR implementation requires access to the SDR's Knobs & Meters (K&M) in order to achieve self-awareness. Due to the lack of a standard K&M API, current CR architectures rely either on APIs provided by concrete SDR platforms, or specify arbitrary APIs that are not standardized by any standards organization. This leads to the situation in which existing CR architectures are rather tightly bound to a chosen SDR platform supported by a (usually large) business unit. Instead of relying on any specific SDR API, in our previous work we proposed a thin and generic interface between a reasoner and a SDR. In this approach the reasoner could access K&M of an SDR using only abstract, ontological terms. In this paper we will further investigate how the ontological terms are mapped to SDR-specific method invocations and show how the ontology-based interface could be used in different Cognitive Engine implementations and lead to CR architectures that are less dependent on the underlying software interfaces.


Model driven engineering to control software radio development (presentation not available)
Lahatra Rakotondrainibe (INSA Rennes, France)

Abstract - SCA waveform development process must be achieved by a set of necessary tools that supports from the algorithmic prototyping and validation to the final implementation of the components including their deployment. For these systems, the hardware platform is heterogeneous and based on General Purpose Processor, Digital Signal Processor and reconfigurable resources like FPGA. To handle the application complexity and the hardware targets, Model Based Engineering (MBE) is used increasingly to provide abstractions without any reference to the target platform. For the whole process development, the MBE approach is based on several tools and formalisms to take into account all the points of view from the algorithmic requirements to the final implementation. The development process manages a set of models that create abstractions of the specification, of the design and the implementation. In this approach, we must face the problem to remain consistency in the set of models and to ensure the SCA standard use in the models. In our approach, we introduce a DSL (Domain Specific Language) to define software-radio rule classification applying on the models.


Porting of an FPGA Based High Data Rate DVB-S2 Modulator (paper) (presentation)
Chayil Timmerman (MIT Lincoln Laboratory, USA); Ivan Corretjer (Naval Research Laboratory, USA); Michael A. Rupar (Naval Research Laboratory, USA); John Glancy (Naval Research Laboratory, USA)

Abstract - This paper covers a high data rate (HDR) DVB-S2 (Digital Video Broadcasting - Second Generation Satellite) modulator implementation that was designed to allow for rapid porting across a multitude of different software defined radio (SDR) platforms and scale accordingly to each platforms capabilities and limitations. Naval Research Laboratory's (NRL) basic digital radio - one (BDR-1) SDR platform was chosen as a good candidate SDR platform to demonstrated the portability and scalability of the modulator implementation. The BDR-1 provided a significantly smaller form factor than the platform originally used to develop the HDR DVB-S2 modulator. It also already had successfully demonstrated an NRL develop HDR waveform implementation, introduced in previous papers, which made it an ideal candidate. This paper will discuss the coding and architectural techniques used in order to increase the portability and scalability of the waveform; the steps taken to port the waveform to the BDR-1; and finally a review of the end results.


A Proposed API for the Information Plane of the WSN Integrated Technical Reference Model (I-TRM) (paper) (presentation)
Babak Beheshti (New York Institute of Technology & Ikanos Communications Corp., USA); Howard Michel (University of Massachusetts Dartmouth, USA)

Abstract - The Integrated Technical Reference Model (I-TRM) for an autonomous Wireless Sensor Network (WSN) has been developed to be used as a guideline to develop a unified and standardized architecture for a diverse array of multi-platform WSNs. Based on the I-TRM proposed by Michel and Fortier, there are three planes to this reference model: The Information Plane, the Control Plane and the Behavior Plane. This reference model lays out a detailed layered model with functional description of each layer described in general terms. The Information Plane puts forward the information processing side of the system. The main focus is on data collection, information aggregation, knowledge generation and presentation. It shows how data is transformed into knowledge. This paper presents the follow up research performed on this I-TRM, by providing a platform independent API to aid designers of WSNs to develop a codified implementation of WSNs. The API has been implemented using nesC in a TinyOS environment, running on the Berkeley Motes.

Tutorial 6F: Software Communication Architecture "Next" Release (presentations)

Session 7A: Security and Encryption

Enhancing Network Security Using 'Learning-from-Signals' and Fractional Fourier Transform Based RF Fingerprints (paper)
Mark Buckner (Oak Ridge National Laboratory, USA); Ethan Farquhar (ORNL, USA); Michael A Temple (Air Force Institute of Technology, USA); Paul Harmer (Air Force Institute of Technology, USA), Miljko Bobrek (ORNL, USA)

Abstract - Wireless Access Points (WAP) remain one of the top 10 network security threats. The goal of this proof-of-concept research is to develop a physical layer aware Radio Frequency (RF) air monitoring system to provide a first-line of defense for network security--stopping attackers before they can gain access to critical infrastructure networks through vulnerable WAPs. This paper presents early results on the identification of 802.11a devices using RF Distinct Native Attribute (RF-DNA) fingerprints produced by the Fractional Fourier Transform (FRFT). These fingerprints are input to a Differential Evolution (DE) optimized "Learning from Signals" (LFS) classifier. The results consider WiFi devices under the most challenging conditions of intra-manufacturer classification, i.e., same-manufacturer, same-model, differing only in serial number. Performance of the FRFT RF-DNA fingerprints will be compared to previously published results using Wavelet Domain (WD), Time Domain (TD) and Spectral Domain (SD) fingerprints.


The International Radio Security Service API for Tactical Radios (paper)
Scott Leubner (Harris Corporation & RF Communications Division, USA); Rafael Aguado Muoz (Indra Sistemas, Spain); Anthony DiBernardo (Harris Corporation, USA); Charles Linn (Harris Corporation, USA); Alvaro Mayol Garrido (Indra Sistemas, Spain); Javier Fernandez Alonso (Indra Sistemas, Spain); Leonard Picone (Harris Corporation, USA)

Abstract - In 2001, the JPEO JTRS established the landmark SCA v2.2, formally defining what would become the military communication standard. The SCA specification defined for the first time what would become the basis of military radio terminals and the pillar architecture to support waveform development. The primary objective of this specification was waveform portability enhancement, allowing independent radio manufacturers to migrate waveforms developed by other vendors onto their platforms. However, over time, the inclusion of export-restricted elements in the Security Supplement impeded the standard's international acceptance. In this context, the Wireless Innovation Forum (WInnF, formerly called the SDR Forum) initiated a International Radio Security Service API (IRSSAPI) working group. Over the past year, this group has been devoted to the development of a truly international Security API standard for radio communications with no export restrictions. In addition, this group has and will continue to act as a catalyst between the WInnF development community and government stakeholders. The paper will show the basis upon which the Security Services API will be based, as well as the main drivers for its definition. The paper will conclude with the main achievements and the expected future work.


A Technical Overview of the International Radio Security Service API (paper) (presentation)
Anthony DiBernardo (Harris Corporation, USA); Scott Leubner (Harris Corporation & RF Communications Division, USA); Rafael Aguado Muoz (Indra Sistemas, Spain); Charles Linn (Harris Corporation, USA); Alvaro Mayol Garrido (Indra Sistemas, Spain); Leonard Picone (Harris Corporation, USA); Javier Fernandez Alonso (Indra Sistemas, Spain)

Abstract - The JPEO JTRS established a new paradigm for software definable radios with their release of the Software Communications Architecture (SCA) specification. This specification details requirements and outlines a framework for software based radio platforms. The intentions of this specification are to foster portability of waveform applications between divergent radio platforms. Beyond an initial historical draft, the JTRS program currently has no provisions for a publically available security API that the broader international community can use to develop portable waveforms. Recognizing a lack of an internationally available security API for SCA based radios, the WInnF organization has developed a security API called the International Radio Security Services API (IRSS API) to fill this gap. This paper introduces and presents a technical overview of the major interfaces supporting wideband networking waveform. Primary focus of the paper will center on the establishment of secure networking channels via network security protocols, including the application of asymmetric key management techniques.

Session 7B: Government Applications

Development of a Low-cost Public Safety P25 Waveform in an OSSIE Environment with the USRP (paper)
Zhongren Cao (University of California, San Diego, USA)

Abstract - Low-cost software communications architecture (SCA) based waveform implementation and porting is a much sought-after feature in the software-defined radio (SDR) community. It not only reduces the acquisition cost to purchase systems and equipment, but also lowers the entry barrier, thus enabling a broader range of organizations to carry out SCA-based SDR research, development and training. This paper describes the development and implementation of a low-cost public safety Project 25 (P25) waveform that has been ported from the SDR-4000, a high-end surrogate JTRS SDR platform, to a low-cost PC and Universal Software Radio Peripheral (USRP) platform. The ported P25 waveform is implemented in an OSSIE environment, which is an open-source SDR core framework based on the JTRS SCA, using Linux as the operating system (OS). The choices of the SDR platform, the core framework and the OS enable a low-cost porting and implementation of the P25 waveform. In the full paper, the porting process is described in detail and lessons learned are discussed.


STRS Waveform Porting for NASA's CoNNeCT Project (presentation)
Dale Mortensen, P. E. (ASRC Aerospace Corp. & NASA Glenn Research Center, USA)

Abstract - As NASA's Communications, Navigation, and Networking reConfigurable Testbed (CoNNeCT) readies for launch to the International Space Station much has been learned from the initial waveform port to one of the SDRs on board. NASA's Glenn Research Center has successfully ported terrestrially-based waveform code from NASA Goddard Space Flight Center onto a space SDR platform built by the Jet Propulsion Lab. A key part of this port was use of the Space Telecommunications Radio System architecture, reducing the porting effort and allowing parallel development of the platform and waveform by separate organizations. Still there are many challenges to waveform integration with a space-based SDR that the STRS architecture has not yet addressed, such as waveform specific platform temperature compensation. Several porting metrics, including level of effort and platform resource utilization, will be presented.


How Should Future Airborne Networks Be Designed, Acquired & Deployed (presentation not available)
Sherin Kamal (Science Applications International Corp.(SAIC), USA)

Abstract - The future of Airborne Networks has taken on added and unique importance for the US military, not just the air force. The reasons for that are briefly reviewed in this paper, as context/background for the paper's discussion of what future military airborne networks should look like given the missions and Concepts of Operations (CONOPS) that are being developed for addressing future wars and conflicts. Deconstructing the architecture of military Airborne Networks is a critical focus of this paper because efforts to date have asked the wrong questions and are saddled with historical limitations. Technology advances today allow us to innovate without abandoning legacy equipment. The paper proposes a different approach to the one-size-fits-all or the pltform-dependent acquisition policies. Both have resulted in mammoth acquisition programs that overlook key requirements for interoperability. The theme is that effective future airborne networks will emerge from how we define the overall problem, not from costly and complex solutions to the wrong problem.


Software-Defined and Cognitive Radio Technology for Military Space Applications (paper)
Joshua Androlewicz (AFRL, USA); Ryan Buffington (Schaffer Corp., USA); Craig Kief (Configurable Space Microsystems Innovations and Applications Center & University of New Mexico, USA); Richard Erwin (AFRL, USA); James Crane (AFRL, USA); Keith Avery (Air Force Research Laboratory, USA); James Lyke (AFRL, USA)

Abstract - Command of the RF spectrum is essential to current and future Air Force operations, and space operations are no exception to this statement. Current military satellite assets provide unique capabilities to the warfighter, particularly communications and broadcast services such as GPS. But even as demand for these services soars due to expectations driven by commercial capabilities, spectrum allocation is at best remaining constant and in danger of contraction due to re-allocations. Furthermore, military systems, including military space systems, must be able to operate under adverse environments, including adversarial environments, which commercial systems do not design to. Finally, there is continual pressure to provide more capability at less cost to efficiently manage budgets. These driving forces have led the Air Force Research Laboratory's Space Vehicles Directorate (AFRL/RV) to initiate a new research program in the development and application of software-defined and cognitive radio technology for military space applications.

Session 7C: Standardization and Education

The ESSOR Programme - Status and way to standardization (paper)
Philippe Margot (OCCAR-EA, Germany)

Abstract - The ESSOR Programme - European Secure Software Defined Radio - has reached an important step end of 2010 with the completion of the ESSOR Architecture definition and the first version of the draft ESSOR Architecture standard. This ESSOR Architecture is being verified and validated in 2011 through its implementation onto six nationally selected platforms. This activity involves OCCAR-EA, the Contracting Authority, and the 6 Nations participating to the ESSOR Programme (Finland, France, Italy, Poland, Spain and Sweden) as well as a4ESSOR as the Prime Contractor and the 6 major communications industries from these 6 Nations (respectively Elektrobit, Thales, Selex Communications, Radmor, Indra and Saab). The results from these implementations and validations of the ESSOR Architecture will allow the ESSOR Architecture to be progressively approved for public release. Since the beginning of 2011, the ESSOR Stakeholders have also started being involved in the Coordination Committee on international SCA standards of the Winnf.


SDR in Electrical Engineering Education: The FlexNets Project (paper) (presentation)
Vuk Marojevic (Polytechnic University of Catalonia, Spain); Ismael Gomez (Polytechnical University of Catalonia & UPC, Spain); Pere Gilabert (UPC, Spain); Antoni Gelonch (Polytechnic University of Catalonia, Spain)

Abstract - Electrical engineering education should give an overview of the complexity of current and emerging systems while providing enough background to the students for being able to understand and eventually participate in the system development. Wireless system engineering, in particular, requires skills in a wide scope of technologies including digital signal processing, software design, real-time execution, parallel and distributed computing, and analog-to-digital conversion techniques. The Escola Politcnica Superior de Castelldefels (EPSC, of the Polytechnic University of Catalonia (Universitat Politcnica de Catalunya - UPC) therefore follows the project based learning (PBL) concept for educating the electrical engineering students and preparing them for their profession. Software-defined radio (SDR) unifies many concepts and methodologies, from radio engineering to computer science. SDR thus adds additional difficulties to common wireless communications practices. Software design and portability are of special importance in SDR research and deployment.

Session 7D: Software Communications Architecture (SCA)

The design and benefits of an SCA based video downlink receiver (presentation)
Lloyd Palum (Harris Corporation, USA)

Abstract - The use of unmanned systems has increased dramatically over the last 10 years. The original systems integrated commercially available technologies to provide quick fielding of a very valuable tactical and strategic resource. Originally UAS system designers were looking for a relatively simple and easy to deploy set of technologies to build the first viable platforms. Using previous generation analog satellite television transmission and reception technology for video down links allowed the UAS to be rapidly and easily deployed. In the wake of the unmanned platforms fielding success there is now a need to evolve the current systems to take on improved capabilities and security. Software defined radio platforms play a critical part in this evolution. In particular, Harris Corporation is helping to field Software Defined Remote Video Terminals based on the popular Falcon III SCA architecture that provide multi-mode wireless video downlink application support in a single tactical battery operated platform. In this presentation, we will explore the benefits of such an approach and how it can aid in the evolution of ISR video distribution.


Developing SCA Based Networking Waveform Applications (presentation)
Ken Dingman (Harris Corp, USA)

Abstract - The Joint Tactical Radio System (JTRS) Software Communications Architecture (SCA) serves as a de-facto international standard defining a set of rules and protocols for military Software Defined Radio (SDR) applications. The European Secure Software Defined Radio (ESSOR) program has adopted the SCA as its base standard for SDR technology, providing diversity and leverage for SCA standards evolution. A key tenant of both the JTRS and ESSOR programs and the use of the SCA is focused on the portability of waveform applications across various radio platforms, thereby facilitating lower cost and shorter time-to-market for the deployment of increased capabilities to war-fighters, in conjunction with improved communications interoperability. This objective is of particularly critical importance for joint force and coalition actions. As the pace on the battlefield accelerates, the need for real-time information is becoming increasingly important hence the demand for development and deployment of IP based networking waveform applications for SCA based radio systems.


The Benefits of Static Compliance Testing for SCA Next (paper) (presentation)
James Ezick (Reservoir Labs, USA); Jonathan Springer (Reservoir Labs, USA)

Abstract - The next generation of the Software Communication Architecture (SCA) specification (SCA Next) introduces several features that will affect the compliance certification process. Among the more significant and high-profile changes are the introduction of multiple supported platform models and support for both CORBA and non-CORBA transport layers. These features, which further abstract the specification away from a uniform hardware/software interface, make constructing an all-purpose dynamic testing platform more difficult. This suggests that a certification plan that relies more heavily on static testing might provide a more versatile and cost-effective approach. In this paper we describe the benefits and implications of static compliance testing in the context of SCA Next. This includes a discussion of which requirements are and are not amenable to static testing, the complexity of defining and customizing tests, the expected performance and limitations of those tests, and a summary of our experience derived from the development of R-Check SCA, our platform for static SCA compliance testing.


Middleware Transports for Embedded Software Radio (paper) (presentation)
Roy Bell (Raytheon, USA)

Abstract - Embedded systems are undeniably migrating from hardware to software, and software systems are undeniably using more standardized software components. Examples include the use of commercial operating systems and middleware products such as web services and CORBA. Some software developers buck the trend by attempting to gain a short-term size or performance advantage using custom software components, but with the increasing speed of processors, increasing size of memory and increasing demand for more functionality; the long-term trend is to use standardized components when they meet the need. This allows developers to reduce time to market or spend their time increasing the functionality and sophistication of their products. The JTRS standard strives to achieve a plug-n-play infrastructure that supports component portability by standardizing the APIs that access and control radio applications and components. These APIs are expressed in both C language and CORBA IDL. Proponents of the CORBA APIs perceive advantages in modularity, reliability, and increased functionality. Proponents of the C language APIs do not extol its virtues, but instead point to perceived CORBA disadvantages in size and performance. We have eliminated these potential disadvantages.

Tutorial 7E: A Graphical Programming Approach to SDR Design and Prototyping with Labview and USRP (presentation)
Sam Shearman (National Instruments, USA)

Tutorial 7F: New Directions in Channelized Receivers and Transmitters (presentation)
fred harris (SDSU, USA)

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