Cost Efficient Testing of Large MIMO DUT in Virtual Electromagnetic Environments

Markus Landmann (Fraunhofer Institute for Integrated Circuits IIS, Germany); Christopher Schirmer (Ilmenau University of Technology, Germany); Mario Lorenz and Wim A. Th. Kotterman (Technische Universität Ilmenau, Germany); Giovanni Del Galdo (Fraunhofer Institute for Integrated Circuits IIS & Technische Universität Ilmenau, Germany); Christian Schneider and Reiner S. Thomä (Ilmenau University of Technology, Germany); Frank Wollenschläger and Christian Bornkessel (Technische Universität Ilmenau, Germany); Matthias Hein (Ilmenau University of Technology, Germany)

Modern vehicles board various radio systems ranging from communication to navigation employing more frequently sophisticated solutions for the radio interface, e.g., antenna arrays. This trend is about to increase dramatically with the introduction of intelligent transport systems (ITS) in the near future. In the field of mobile communications, it is possible to test MIMO systems over the air (OTA) under realistic yet repeatable conditions in a laboratory environment due to the limited size of the handhelds. In fact, wave filed synthesis (WFS) can be applied to emulate the spatial characteristics of the radio propagation channel. However, for large devices under test (DUTs), such as a vehicle, WFS is prohibitively expensive due to the number of channels which the emulation equipment requires. In this contribution, a cost efficient MIMO OTA test method to evaluate systems that are installed on large objects is presented. With this method, self-interference, interference, as well as co-existence of various other systems that are installed on the vehicle are accounted for during a realistic over the air test.

 

SDR-Based Radio Channel Measurements in sub-GHz Unlicensed Frequency Bands

Hendrik Lieske (Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Germany); Thomas Lauterbach (Georg-Simon-Ohm-Hochschule - University of Applied Sciences, Spain); Joerg Robert (Friedrich-Alexander University Erlangen-Nuremberg, Germany); Gerd Kilian (Fraunhofer IIS, Germany); Albert Heuberger (Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany)

We present a newly developed measurement system for studying the long-term properties of indoor-to-outdoor radio channels at 169.4 - 169.475, 433 - 434.8 and 863 - 870 MHz. It comprises a large number (up to 50) of battery operated low cost transmitters that are spread in the area of interest, e.g. in different rooms of a building or in different houses. They are able to send narrow-band MSK modulated data packets in 3, 7 and 27 channels in the three frequency bands every few minutes for several weeks without maintenance. The receiving station uses a software defined radio front end (Ettus USRP B210) and two antennas for each band. The large bandwidth of the USRP and the high signal processing power of a PC allows to receive all channels simultaneously and to decode packets received from the different transmitters. Signal level, SNR and BER are estimated for each packet and written to an XML data file for further processing. We describe the signal design and the packet structure, the algorithms used for decoding and the performance of the software defined radio receiver with respect to synchronization capability and sensitivity. For signal level estimation, the whole system was calibrated in a wide range (-120 dBm to -40 dBm) and the performance of the rubber antennas used on the transmitters was measured. A first field trial making use of the system was carried out at the Fraunhofer Institute for Integrated Circuits IIS building at Erlangen from August to October, 2014. It showed the feasibility of the system design and the long-term reliability of transmitter and receiver hard- and software. Initial results on the variability of signal levels over several days, on frequency selectivity and path loss of indoor-to-outdoor channels in the range 10 m to 100 m are presented.

 

Realistic Channel Modeling for Mobile Ad-Hoc Networks in the VHF and UHF Band

Jörg Fischer (Fraunhofer Institute for Integrated Circuits IIS, Germany)

This talk deals with the problem of modeling the channel characteristics for the links in a mobile ad-hoc network (MANET). In contrast to broadcasting and cellular applications, the links of a MANET cannot be analyzed independently. Thus, a realistic modeling of the correlation of the links is required for a thorough evaluation of routing techniques and network protocols for future communications systems. Furthermore, the channel characteristics encountered by the links of a MANET, especially in the VHF and lower UHF frequency band, differ significantly from the estimates of models aiming at broadcasting and cellular applications. The talk presents a new MANET channel modeling approach which is based on extensive measurements in typical mobile-to-mobile scenarios and comprises path loss, correlated shadow fading and multi-path modeling. The combined model can easily be integrated in network simulators and allows for more realistic estimates for the design of future and the evaluation of existing mobile-to-mobile communication systems than the models currently in use.

Licensed Shared Access (LSA) Field Trial Using LTE Network and Self Organized Network LSA Controller

Seppo Yrjölä (Nokia Solutions and Networks, Finland)

This paper presents the results from the over the air field trial of the new Licensed Shared Access concept utilizing a TD-LTE radio access network in the IMT spectrum band 40 (2.3-2.4 GHz) in Finland. In the field trial, the LTE network shares the spectrum with Program Making and Special Events (PMSE) incumbent. New LSA concept elements, LSA Repository for incumbent protection information and LSA Controller for controlling the mobile broadband network in the same spectrum band are implemented in the trial environment. The trial utilizes commercially available network elements like multimode multiband terminals, LTE base stations, core network and network management system. Incumbent spectrum usage data is collected to the LSA Repository, which further converts it to spectrum availability information for the LSA controller. The developed LSA Controller consists of Minimum Separation Distance and Protection Zone Optimization algorithms to analyze and optimize base station parameters according to the spectrum availability information and uses network management system to configure the radio network accordingly. This is the first LSA trial which has LSA controller implemented as Self Organizing Network (SON) solution fully integrated into commercial Operational Support System (OSS). Incumbent users' rights are protected by evacuating the overlay LSA TD-LTE band and handing users over to coverage FDD LTE network when requested by the incumbent spectrum user. Numerical results are presented to quantify the duration of the LSA work flow steps in particular in emergency evacuation phase. The trial shows that the LSA concept can be implemented with commercial available network elements and a minimum amount of new software and hardware components. The performance results on the LSA system workflow indicate that in the PMSE use case the usage of the LSA band can be managed timely manner and the incumbents' rights can be protected. Introduction Spectrum is one of the most in-demand resources in our digitalizing information economy. We have witnessed the exponential growth of wireless services to access information, enjoy content, and conduct commerce from mobile devices anywhere, anytime. The number of mobile broadband subscribers and the amount of data used per user is set to grow significantly over the coming years [Cisco2014] leading to increasing spectrum demand. In addition to traditional exclusively licensed spectrum with long term licenses, there are globally allocated exclusive International Mobile Telecommunications (IMT) bands that are currently restricted by the incumbent use, but are mostly unused in time and location. These underutilized spectrum bands has recently been considered as an opportunity by regulators, industry and research community in finding sufficient supply of spectrum resource to meet the growing demand of the mobile broadband (MBB) communication on time. The most prominent recent spectrum sharing concepts under study in the technology, policy and business domains are the 3 tier Spectrum Access System (SAS) from the US [PCAST 2013] [FCC R&O 2015] and the Licensed Shared Access (LSA) [ECC 205 2014] from Europe. LSA is a novel spectrum sharing concept introducing spectrum sharing between a Mobile Network Operator (MNO) and another type of incumbent spectrum user. The LSA concept has received interest in both the European regulation and standardization for coordinating the spectrum access of both the incumbent and MNO in the same IMT spectrum band 40 (2.3-2.4 GHz). European Commission defines LSA as [RSPG 2013], "a regulatory approach aiming to facilitate the introduction of radio communication systems operated by a limited number of licensees under an individual licensing regime in a frequency band already assigned or expected to be assigned to one or more incumbent users. Under the Licensed Shared Access (LSA) approach, the additional users are authorized to use the spectrum (or part of the spectrum) in accordance with sharing rules included in their rights of use of spectrum, thereby allowing all the authorized users, including incumbents, to provide a certain QoS". In the LSA concept [RSPG2013] [ECC 205] spectrum sharing is allowed between an incumbent spectrum user and a licensee in a binary way so that both have exclusive individual access to a spectrum at a given time and location. The spectrum regulator is responsible for identifying LSA spectrum to be licensed, defining the sharing framework consisting of rules and conditions for sharing as well as granting the license to the LSA licensee. Based on the national framework the incumbent and LSA licensee negotiate the private commercial sharing agreement under the permission and governance of the regulator. In the voluntary LSA framework and agreement the incumbent spectrum user defines the part of its spectrum that can be used for sharing with the LSA concept, the license duration and geographical area. This paper focuses on demonstrating the LSA concept and validating key performance parameters for sharing between an MNO and another type of incumbent, in particular Program Making and Special Events (PMSE) spectrum user in the Finnish use case. The LSA concept has been field trialed the first time in Finland by the Cognitive Radio Trial Environment (CORE) project consortium in April 2013 [IEEE VTM] followed by iteratively updated features demonstrated in April 2014 [DySpan'14] and November 2014 [ETSI RRS plenary]. To authors knowledge no other LSA field trial environment has been reported to date. The field trial presented in this paper enhances the CORE environment further by introducing first time LSA controller implemented as Self Organizing Network (SON) solution fully integrated into commercial Operational Support System's (OSS) with advanced incumbent protection algorithms needed to optimize protection zones to protect the incumbent's business while maximizing availability for the licensee. The rest of this paper is organized as follows. The Finnish LSA trial environment and key elements are introduced in Section 2. Section 3 presents field trial set up, work flow and operations. Performance evaluation and measurement results from the LSA trial using live commercial LTE network in the 2.3 GHz band are summarized in Section 4. Finally, conclusions are drawn in Section 5.

 
Sub-Nyquist Wideband Acquisition and Spectrum Sensing of Multiband Signals

Anastasia Lavrenko and Florian Roemer (Ilmenau University of Technology, Germany); Giovanni Del Galdo (Fraunhofer Institute for Integrated Circuits IIS & Technische Universität Ilmenau, Germany); Reiner S. Thomä (Ilmenau University of Technology, Germany)

The task of acquiring a wide frequency band consisting of multiple communication sub-bands is crucial in a number of applications including cognitive radio (CR), spectrum monitoring, and radio surveillance. Recent developments in the processing of sparse and compressible signals opened up the possibility to acquire wideband signals at sub-Nyquist sampling rates, provided that the signal's energy is distributed over only a fraction of the total received bandwith. The primary aim of compressive spectrum sensing is to detect the parts of the spectrum that are occupied based on the received sub-Nyquist signal measurements. In this talk, we discuss the approaches to wideband acquisition and spectrum sensing of sparse multiband signals. Moreover, we show that in a generic sub-Nyquist sampling framework one can perform coarse wideband sensing directly from the compressed measurements without the need to perform full signal or power spectral density (PSD) recovery.

 

Cognitive PMSE for Spectrum Sharing at UHF

Georg Fischer, Johannes Brendel and Steffen Riess (University of Erlangen-Nuremberg, Germany)

This talk reports about work in ETSI STF386 pre-standardisation and a German national Research Project by BMWI named C-PMSE dealing with cognitive interference management to allow for coexistance of PMSE, DVB-T and LTE at UHF Band.

DFC++ - A novel framework approach for flexible signal processing on embedded systems

Dominik Soller, Thomas Jaumann and Gerd Kilian (Fraunhofer IIS, Germany); Joerg Robert (Friedrich-Alexander University Erlangen-Nuremberg, Germany); Albert Heuberger (Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany)

Development of modern SDR based communication systems can be accelerated significantly by the use of processing frameworks. The evolution of SDR and the departure from digital representations of classical radio architecture towards more abstract software systems raises new requirements of flexibility and versatility. The DFC++ processing framework addresses those requirements by employing modern programming concepts and flow control mechanisms to allow for variable data rates, dynamic component connections and arbitrary port configurations. Another important trend is the integration of specialized embedded platforms in the software radio domain. The rapidly increasing performance and efficiency of embedded processors enables the deployment of SDR systems in more space and power constrained environments. By relying exclusively on C++ and minimizing external dependencies DFC++ is specifically designed for excellent portability and adaptability to support current and future designs while maintaining high performance and ease of use. This paper introduces the key aspects of the DFC++ processing framework focusing on the reference pointer based data transport mechanisms responsible for the propagation of user data between different processing components.

 

Usage of Software Defined Radio in DCP Satellite Ground Stations

Oliver Harrmann (SCISYS Deutschland GmbH, Germany)

The collection and distribution of environmental data from Data Collection Platforms (DCP) is one of the core services for many meteorological satellites around the globe. DCP stations transmit data from various meteorological and environmental sensors in the UHF band via satellites. Depending on the Data Collection System, the DCP band is subdivided into several hundred DCP channels. Each DCP station is typically assigned to a specific DCP channel and transmission time slot. The meteorological satellite provides a DCP transponder converting the full DCP band into L-Band. The L-Band signal is received by the Ground Station. In order to cope with the high number of DCP channels in parallel, the L-band signal is down converted to an IF frequency, automatically gain controlled, filtered and then digitized. At this point the flexible implementation of a software defined radio receiver starts. The architecture of the SDR system is presented showing not only it's real time capabilities but also post processing steps for detailed signal analysis helping to identify defect and/or erroneous DCP transmitters. Furthermore different signal processing extensions, e.g. for compensation of antenna phase ripple effects are presented. The future METEOSAT Third Generation DCP concept will be elaborated also showing the flexibility of SDR implementation w.r.t. the adaptation of the new concept for SDR receivers (Rx). In addition, SCISYS is currently developing a new DCP transmitter (Tx) in the framework of the ESA's ARTES 5.1 technology programme. In this project legacy DCP transmitters are developed and in addition a new satellite-to-ground ICD for future DCP missions is prototyped.

 

Exploiting Cyclic Features for Jammer Detection in Wideband Cognitive Radios

Tassadaq Nawaz and Muhammad Ozair Mughal (University of Genova, Italy); Lucio Marcenaro (Università degli Studi di Genova, Italy); Carlo S Regazzoni (University of Genoa, Italy)

Cognitive radios (CRs) have been proposed as a promising solution for improving spectrum utilization through opportunistic spectrum sharing. However, security issues pertaining to CR technology are still under studies. One of the prevailing such issues are radio frequency jamming attack, where adversaries are able to exploit on-the-fly reconfigurability potentials and learning mechanism of CRs in order to devise and deploy advanced jamming tactics. In this paper, we propose a new algorithm for jammer detection in wide-band (WB) cognitive radio networks. Our proposed approach considers a wide band (WB) which consists of multiple fixed length narrow-band sub-bands (SB). These SBs can be occupied by narrow-band signals such as binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), tone (sine or cosine) or any other narrow-band signal. These narrow-band signals can be legitimate users or jammer. The jammer can be in a free SB or can jump to an occupied SB of legitimate user. In our work, cyclostationary based classifier is proposed to reliably identify the signal type of unknown signals. The proposed system assumes no a priori knowledge of critical signal statistics such as carrier frequency, carrier phase, or symbol rate. The cyclostationary classification is implemented through strip spectral correlation algorithm (SCCA), is used to get spectral correlation function (SCF) or spectral coherence function (SOF), which is in fact a true measure of the correlation between the spectral components of received signal. A significant benefit of SCF is its insensitivity to additive noise. Since the spectral components of white noise are uncorrelated, it does not contribute to the resulting SCF for any value of α≠0 (cyclic frequency). The performance of proposed algorithm is evaluated with the help of monte-carlo simulation. Here, we consider BPSK and QPSK as legitimate signals and sine wave as a jammer. The received signals are considered to be affected by additive white Gaussian noise (AWGN). We design system in such a way that WB is divided in four SBs. We placed signals BPSK and QPSK in SB1 and SB4 while jammer was placed in SB2. The SCF of received signal is calculated by SCCA, which gives the signal features like cyclic frequency (α), spectral correlation density (Sx) and spectral frequency (f). We used feature-based approach (FB) to identify the signals as legitimate or jammer. For each SB, some feature of received signal such α, Sx (α -profile) are compared with licit user database to classify the observed signal as licit user or a jammer. Finally, we plot jammer detection rate (β) versus signal to noise (SNR) ratio. The results show that this technique perform very well under low SNR conditions. The β value is approximately 0.9 for SB2 at -5dB SNR. However, β is 0.7 for SB1and 0.6 for SB4, due to miss classification of legitimate signals at -5dB SNR. The β is significantly increased for SB2 and its value reaches to 1 at 5dB SNR. On other hand β is reduced to 0.2 and 0.1 for SB1 and SB4 respectively at 5dB SNR. After that we configure our system in such that SB4 is occupied by QPSK signal while jammer jumps into SB1 thus jamming the SB1 which is occupied by BPSK. In this configuration β is 0.9 for SB1 (due to abnormal changes in Sx value) and 0.6 for SB4 at -5dB SNR. The β values are 1, 0.1 for SB1 and SB4 respectively at 5dB SNR. In next system configuration, SB1 is occupied by BPSK signal while the jammer jumps from SB2 to SB4 in order to jam the QPSK signal. In this case β is 0.9 for SB4 (due to abnormal changes in Sx value) and 0.7 for SB4 at -5dB SNR. The β values are 1, 0.2 for SB1 and SB4 respectively at 5dB SNR. The results show that this technique can be used for detection of jammer with high detection rate at low SNR due to its insensitivity to AWGN noise.

Cross-layer Resource Allocation for 5G Heterogeneous Software Defined Networks

Giulio Bartoli and Dania Marabissi (University of Florence, Italy); Renato Pucci (CNIT - University of Florence, Italy); Luca Simone Ronga (CNIT, Italy)

The demand for pervasive wireless access and requirements for high data rates are expected to grow significantly in the near future. In this context, the deployment of Heterogeneous Networks will enable important capabilities such as high data rates and traffic offloading, providing dedicated capacity to homes, enterprises, and urban hotspots. Despite HetNet technology will be beneficial for future wireless systems in many ways, the massive cell diffusion has as consequence an exponential increase of the backhaul traffic that can create congestion and collapse of the backhaul network. In this paper we consider a Software Defined Network (SDN) architecture where different access nodes are part of an infrastructure layer that is connected and managed by the SDN control software through OpenFlow APIs. An appropriate high level SDN application is responsible for the efficient coordination among the network layers of access nodes and to take dynamic joint decisions about the resource usage. Due to the complexity of the decisional process in the SDN controller, also subject to tight time constraints, a cognitive parallel logic is proposed. SDN abstraction provides a simplified view of underlying network to the RAN SDN application, passing to it all the required augmentations. In particular we propose a cross-layer approach that takes into account both the data traffic load of each cell in the HetNet and the capacity of the backhaul links that are available to connect the cells. The proposed iterative procedure tries jointly to optimize the distribution of the traffic in the backhaul network and the UEs cell association with the goal of minimizing the unsatisfied UEs requests.

 

Increasing receiver dynamic range for Low Power Wide Area Networks

Gerald Ulbricht, Jakob Kneißl, Josef Bernhard and Gerd Kilian (Fraunhofer IIS, Germany)

The connectivity of embedded devices, known as the "Internet of Things", is expected to be the next digital revolution [1]. According to [1], the industry estimates more than 20 billion connected devices in 2020. Low Power Wide Area Networks (LPWAN) will enable battery powered devices to communicate with each other. These LPWANs make use of frequency bands allocated for short range devices allowing license-exempt operation. As a consequence, interference will increase from a fast growing number of devices transmitting within the sparsely available frequency resources. Telegram splitting is proposed to mitigate loss of data due to collisions with telegrams transmitted by other devices[2]. The telegram, containing information (e.g. sensor data) and header, is split into several sub-packets. These sub-packets are sent with transmission pauses on different frequencies (frequency hopping). With this, interference will only affect single sub-packets and lost information can be reconstructed by error correction mechanisms. At the receiving side, a low-cost software defined radio platform like the USRP (Universal Software Radio Peripheral) is used sampling the complete interested frequency band. The telegrams of the smart devices are extracted from the samples by digital signal processing. In a typical scenario, a plurality of telegrams is received at different frequencies and signal strength. High dynamic range of the receiver is required to demodulate the telegram of a remote object in the presence of a strong interfering signal. This paper analyzes the capability of a stacked analog-to-digital converter (ADC) approach [3] to increase the dynamic range of the analog-to-digital interface of such a receiver. The antenna signal is fed to both receivers of the platform. The AGC of the receivers is frozen at different levels. The right level difference and dedicated combination of the two signals can provide a significant increase of the dynamic range. [1] "The Internet of Things: making the most of the Second Digital Revolution", https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/409774/14-1230-internet-of-things-review.pdf [2] Kilian, G.; Breiling, M.; Petkov, H.H.;, H.; Beer, F.; Robert, J.; Heuberger, A., "Increasing Transmission Reliability for Telemetry Systems Using Telegram Splitting," Communications, IEEE Transactions on , vol.63, no.3, pp.949,961, March 2015 [3] Ulbricht, G.; "Dynamic Range Extension for HF Receiver Frontend", IEEE Radio and Wireless Symposium, 20. - 23. Januar 2013 in Austin, TX

Licensed Shared Access Field Trial utilizing Self Organized Network LSA Controller

Seppo Yrjölä, Vesa Hartikainen and Lucia Tudose (Nokia Solutions and Networks, Finland); Jaakko Ojaniemi (Aalto University, Finland); Arto Kivinen and Jarkko Paavola (Turku University of Applied Sciences, Finland); Marko Palola (VTT Technical Reseach Centre of Finland, Finland); Tero Kippola (Centria University of Applied Sciences, Finland)

This paper presents the results from the over the air field trial of the new Licensed Shared Access concept utilizing a TD-LTE radio access network in the IMT spectrum band 40 (2.3-2.4 GHz) in Finland. In the field trial, the LTE network shares the spectrum with Program Making and Special Events (PMSE) incumbent. New LSA concept elements, LSA Repository for incumbent protection information and LSA Controller for controlling the mobile broadband network in the same spectrum band are implemented in the trial environment. The trial utilizes commercially available network elements like multimode multiband terminals, LTE base stations, core network and network management system. Incumbent spectrum usage data is collected to the LSA Repository, which further converts it to spectrum availability information for the LSA controller. The developed LSA Controller consists of Minimum Separation Distance and Protection Zone Optimization algorithms to analyze and optimize base station parameters according to the spectrum availability information and uses network management system to configure the radio network accordingly. This is the first LSA trial which has LSA controller implemented as Self Organizing Network (SON) solution fully integrated into commercial Operational Support System (OSS). Incumbent users' rights are protected by evacuating the overlay LSA TD-LTE band and handing users over to coverage FDD LTE network when requested by the incumbent spectrum user. Numerical results are presented to quantify the duration of the LSA work flow steps in particular in emergency evacuation phase. The trial shows that the LSA concept can be implemented with commercial available network elements and a minimum amount of new software and hardware components. The performance results on the LSA system workflow indicate that in the PMSE use case the usage of the LSA band can be managed timely manner and the incumbents' rights can be protected.

 

Cellular Baseband Development Platform with an open RF Interface

Benjamin Weber, Harald Kröll, Stefan Zwicky and Qiuting Huang (ETH Zurich, Switzerland)

Cellular modems have different architectural demands, depending on which features of the cellular standard they support. This leads to a variety of baseband processing architectures ranging from dedicated VLSI implementations to processor-centric architectures with accelerators. In this paper we present a development platform based on an RF-board with an open FPGA Mezzanine Card (FMC) interface for baseband algorithm investigation and implementation. The interface allows arbitrary FPGA/DSP boards to be connected. As an example we present an GSM/Evolved EDGE modem based on the platform.

Interoperabilty & Airborne operations
Fabrice Fontanier (Rockwell Collins)

How to introduce Dynamic Spectrum Access technology in NATO tactical communications
Vincent Le Nir (RMA Belgium)

To facilitate the introduction of Dynamic Spectrum Access (DSA) technology and associated dynamic spectrum management (DSM) procedures in military tactical radio communication, a roadmap was presented to NATO CaP3 military session in Oct 2012. The main objective of the roadmap was to create a dedicated band for cognitive radio, in the hope that this would take away uncertainties about spectrum regulations and be a sufficient incentive for military communication industry to start investing and developing products. This paper describes the proposed roadmap and formulates the critics of the NATO spectrum managers (CaP3) on this proposition. Taking into account the remarks of CaP3, a possible way ahead is described. The most promising idea is to create a Military dual-priority band that would take into account the existing saturation of the VHF/UHF band, and meanwhile create a clear spectrum access model for future DSA systems.

 

Tactical Radio Coalition Interoperability Solution Facilitated by ANW2 AND NINE

Igor Spivak (Harris Corporation, USA)

Multinational coalitions have become prevalent in military operations over the past several decades. In many instances, communications issues have hindered effective dissemination of information at various levels of military command structures to all required parties. These communications issues have been attributed to a variety of factors including: proprietary, non-interoperable communications devices, lack of common waveform interoperability standards, lack of common COMSEC/TRANSEC key management, generation and distribution infrastructure, etc. To mitigate these issues, temporary stop-gap solutions have been developed; however, a comprehensive coalition interoperability strategy must still be defined. Harris Corporation, RF Communications division has developed the Adaptive Networking Wideband Waveform (ANW2). The ANW2 is a wideband networking waveform that supports simultaneous secure voice, data and video services for up to 30 networked nodes. The ANW2 has been implemented in both NSA certified, Type 1 high grade radio platforms, as well as commercial, non-Type 1 tactical radio platforms. This paper presents a potential candidate solution to solve the coalition interoperability problem in the tactical radio domain. The proposed solution is based on ANW2, integrated with Network and Information Infrastructure (NII) Internet Protocol Network Encryption (NINE) specification to achieve a standards based, interoperable high grade radio mode that can be implemented as an SCA waveform and ported to a variety of tactical radio platforms.

On the Implementation of the NATO NB WF with Low-Cost SDR Platforms

Vincent Le Nir (RMA Belgium)

There is currently no narrowband Combat Net Radio (CNR) STANAG waveform for international and combined missions providing interoperability in Network Centric Operations (NCO). The principal objective of the Narrow Band Waveform (NBWF) is to achieve coalition interoperability within lower tactical levels.  Military Software Defined Radio (SDR) equipment provides the flexibility to incorporate new waveforms and functionalities without having to upgrade or replace hardware components. Therefore, the SDR technology provides an efficient and inexpensive way to implement the NBWF. The principal objective of this presentation is to demonstrate the implementation of the NBWF with low-cost SDR platforms, such as the Universal Software Radio Peripheral (USRP). More specifically, the physical layer and some parts of the data link layer of the NBWF are implemented in software. The NBWF uses bandwidths of 25 KHz up to 50 kHz with on-air bit rates up to 80 kbps in the VHF or lower UHF bands. The NBWF has a Time Division Multiple Access (TDMA) structure with random access possibilities. This presentation gives an idea of the effort required to port the NBWF from a basic implementation intended for simulations to a more advanced implementation with low-cost SDR platforms. As the STANAGs of the NBWF are being ratified, this presentation provides insights for implementing the NBWF on more sophisticated military SDR platforms.

 

Modular Waveform Design for Re-use and Incremental Evolution

Boyd Buchin, Thorsten Müller, Henrik Schober and Rainer Storn (Rohde & Schwarz, Germany)

The Software Communications Architecture (SCA) specification describes a paradigm for software defined radio development focused on enhancing waveform portability. The SCA accomplishes this by defining a set of requirements that formalize the separation of the waveform applications from the radio platform. One important aspect is the standardization of the communication interfaces between the different components of a waveform and between the waveform components and the operating environment. Based on the ideas of standardized interfaces, a modular approach that encompasses all the stages of the design and implementation of a waveform is a key factor to enable flexibility in the further evolution of the waveform and an efficient development process. In this presentation a modular design approach will be explored that starts with the definition of the first requirements of a waveform and its high level design, stretches over the complete development process to the release of the waveform and its maintenance in operation, which - for military systems - can lasts over several decades.

On the Design of Hierarchically Modulated BICM-ID Receivers with Low Inter-Layer Interferences

Matthias Tschauner and Md. Farhan Tasnim Oshim (Fraunhofer FKIE, Germany); Marc Adrat (Fraunhofer FKIE / KOM, Germany); Markus Antweiler (Fraunhofer FKIE, Germany); Benedikt Eschbach (RWTH Aachen University, Germany); Peter Vary (RWTH Aachen, Germany)

In this paper, we present a novel methodology to optimize hierarchically modulated Bit Interleaved Coded Modulation with Iterative Decoding (BICM-ID). As shown in our previous work [1], hierarchically modulated BICM-ID allows designing receiver with different configurations of code rate and modulation order. Even though the configurations are different, all realizations are able to decode the same transmit signal on the air, but with different fidelity. The set of configurations supports a wide range of receivers with varying processing capabilities, ranging from low for handhelds up to high for vehicular mounted radios. In the hierarchical design, the base layer carries the elementary information which will be exploited by all receivers for the fundamental reconstruction of the originally transmitted source signal. The enhancement layer carries additional error protection information which can be utilized by the receivers with high processing capabilities for e.g. coverage / range extensions. However, the first simulation results shown in [1] revealed that, if compared to non-hierarchical receivers, hierarchical receivers loose performance in terms of bit error rate because of the inter layer interferences. These result from the additional constraints in a hierarchical receiver design. To overcome / minimize these negative influences, we developed a novel algorithm to optimize the signal constellation in hierarchical modulation schemes. The novel algorithm jointly optimizes a set of critical parameters, e.g. bit error probability Pb,layer and the harmonic mean distance d2h,layer, for each layer. The harmonic mean distance d2h,layer is an important measure in BICM-ID scheme which allows predicting the theoretically achievable performance gains. Due to the contrary nature of these critical parameters, the algorithm typically converges after several iterations to a specific modulation scheme. This scheme considers all critical parameters and can be interpreted as the best possible trade-off among them. The system designer is able to tune the optimization process by a convergence weight for each critical parameter. The adverse effects of the inter layer interferences can be reduced. Finally, we used our novel algorithm to design a new modulation scheme (based on an initial 64-QAM) for a hierarchically modulated BICM-ID system. Simulation results show that the optimized modulation schemes outperform the traditional schemes [1] in terms of bit error rates for different layers and in a wide range for a given channel condition Es/N0. [1] M. Adrat, et al. "On Hierarchical Modulated BICM-ID for Receivers with Different Combinations of Code Rate and Modulation Order", SDR15-WInnComm, pp. 129-134, San Diego, USA, March 2015

 

Advanced Low Power, High Speed Nonlinear Signal Processing: An Analog VLSI Example

Giuseppe Oliveri (Ulm University, Germany); Mohamad Mostafa (Deutsches Zentrum für Luft- und Raumfahrt (DLR), Germany); Werner G. Teich (Ulm University, Germany); Juergen Lindner (Uni Ulm, Germany); Hermann Schumacher (Universität Ulm, Germany)

We revisit the topic of signal processing with analog circuits and its potential to increase the energy efficiency. A vector equalizer based on a recurrent neural network structure is taken as an example to demonstrate what can be achieved with state of the art in VLSI design. First measurements of our analog VLSI circuit confirm the possibility to achieve an energy efficiency of about 36 TFlops/Watt, which is an improvement factor of three to four orders of magnitude compared with today's most energy efficient digital circuits.

EDA Perspective on SDR Standards

Philippe Cambraye (EDA)

 

Adopting WINNF transceiver facility for spectrum sensors

Tomaz Solc (Jozef Stefan Institute, Slovenia)

An implementation of the Wireless Innovation Forum Transceiver Facility was developed for VESNA SNE-ESHTER, a specialized spectrum sensor deployed in wireless testbeds within the FP7 CREW project. The goal was to simplify experimentation and portability of experiments. The C++ library that was developed runs on the host PC and implements an event-based scheduler and an asynchronous interface conforming to the Transceiver Facility specification. The library communicates with the sensor over a serial line and does not require modification of the spectrum sensor's firmware. We present the challenges encountered and show some latency benchmarks of this Transceiver Facility implementation. Finally, we provide some suggestions on how the Transceiver Facility could be improved in future versions to better support such hardware.

 

Test Procedures for Software Defined Radio Platforms

Christopher Laske (Fraunhofer Institute for Integrated Circuits, Germany); Felix Auer (Fraunhofer-Institut für Integrierte Schaltungen IIS, Germany)

To test tactical radios according to standardized procedures, the "International Test Operations Procedure" (ITOP) is available. The ITOP was compiled 1993 for analog transceivers and 1995 for digital transceivers in a joint effort by the United States, France, and Germany. The targeted equipment under test for the ITOP is a complete radio for one fixed waveform, or at most a small set of fixed waveforms, with a defined user interface, most commonly in the form of analog audio for speech. With the advance of Software Defined Radio, the performance of radio platforms now is strongly dependent on the actually loaded Waveform Application (WFA) and can change significantly for different WFA. Thus, testing such a radio for one or even several WFA will give performance data for those WFA, but might not reveal the true performance of the platform as is. However, with an increasing number of different SDR-platforms on the market and more and more different waveforms running on these platforms, a comprehensive understanding of their performance independent of a dedicated waveform is of increasing importance, be it for finding the best platform for one's needs, just comparing platforms, or determining the applicability of a platform for new or future waveforms. For those purposes, the ITOP is not well suited. The Fraunhofer Institute for Integrated Circuits started an effort to mitigate these drawbacks by defining test procedures, based on the existing ITOP, which are applicable for testing the RF performance of actual SDR-platforms independent of a fixed waveform. To validate those procedures, they will be implemented in a laboratory test setup and measurements on exemplary SDR-platforms will be made. The goal is to complement the existing ITOP and provide standardized and widely accepted procedures for characterizing and comparing SDR-platforms in cases where performance data for fixed waveforms is not sufficient or a suitable WFA for the platform is not available. In this presentation, the actual status of this effort shall be shown, together with results from first implementations and measurements.

Cognitive Multi-Radio as Enabler for Deterministic Dynamic Spectrum Access

Matej Kloc (University of Erlangen-Nuremberg, Germany); Norman Franchi (Dresden University of Technology, Germany); Markus Gardill and Robert Weigel (University of Erlangen-Nuremberg, Germany)

Cognitive radio (CR) is a promising approach to enable dynamic spectrum access (DSA) and to handle spectral efficiency in licensed frequency bands. In this presentation, two new concepts, called cognitive multi-radio (CMR) and deterministic dynamic spectrum access (D-DSA), are introduced. These concepts help to increase the spectrum agility and hence to improve the deterministic broadband spectrum access in unlicensed industrial, medical and scientific (ISM) bands, where shared spectrum lead to interferences and/or collisions, which consequently degrade transmission performance. Here, the CMR-based D-DSA approach is discussed in context with industrial wireless communications (IWC), where a real-time capable transmission behavior with high determinism, high reliability and low-latency (round-trip latency budget ≤ 1 ms) is required. In addition, a CMR hardware architecture, which is based on the software-defined radio (SDR) principle, is proposed.