Feasibility Assessment in Model Based Environments

The RESCUE project proposes a novel multi-route communication technology design targeted for multi-hop networks, based on cooperative decode-and-forward (DF) relaying allowing intra-link errors and utilizing distributed turbo codes. This deliverable provides a report of the RESCUE Lossy Forwarding (LF) concept implementation and evaluation in a software defined radio platform. Performance analysis proved that RESCUE LF technique performs always better than the baseline Selective Decoding-and-Forward (SDF) with or without joint decoder in the destination node. In the case when the relay node is close enough to the source node to establish a lossless radio link the performance of the RESCUE LF is close to the SDF with joint decoder. However, when the distance between source and relay node is too large to establish a lossless radio link, and there are errors in the relay node after decoding, the RESCUE LF significantly outperforms SDF. Keyword list: GNU Radio, Software Defined Radio, distributed turbo code, joint decoder, lossy forwarding, multi-hop communication, wireless networks, Disclaimer: Ref. Ares(2015)5326106 24/11/2015 RESCUE D2.3 Version 1.0 Page 2 (67) Executive Summary The main goal of the RESCUE project – “Links-on-the-fly Technology for Robust, Efficient, and Smart Communication in Unpredictable Environments” is to enable wireless communication in devastated areas where the partially destroyed communication infrastructure can operate only with the limited range. In case of natural disasters like earthquakes, tsunami or fire over a large area, one of the most important tasks is to extend the wireless network coverage in order to enable fast and efficient rescue operations. Therefore there is a need for robust technologies that can allow coverage extension in a reliable manner. One of the possible and promising solutions to this problem is the Lossy Forwarding concept we propose in RESCUE. Lossy Forwarding is a distributed source coding (DSC) technology. In the conventional Decode-andforward relaying, relay forwards only correctly decoded frames. Lossy forwarding allows a relay to forward a message even if errors have been detected after decoding. At the destination, a joint decoding technique exploits the high correlation of the messages received via different network paths thus extending wireless network range. Deliverable D2.3 is a report of the implementation and verification of the RESCUE concept in the Software Defined Radio (SDR) platform based on USRP hardware and GNU radio framework. This implementation constitutes a step towards the hardware implementation of the RESCUE concept developed within WP1, WP2 and WP3 in a full radio proof of concept. The research and initial ideas have thus far been verified with MATLAB simulations. However, critical parts of the code, especially requiring a lot the computational power, were also implemented in C/C++. This deliverable consists of two chapters. In section 2, a detailed description of implemented software modules and GNU Radio blocks was presented. This section is divided into three main subsections. In subsection 2.2 a RESCUE source node implementation is presented. Subsection 2.3 consists of description of the RESCUE destination node and finally subsection 2.4 presents the relay node. Section 3 contains simulation results analysis obtained from the use of software defined radio implementation described in section 2. It starts with subsection 3.1 where the simulation software and models are presented. Then, in subsections 3.2 and 3.3 simulation scenarios, parameters and used channel models are described. Subsections 3.4 and 3.5 provide a detailed simulation analysis of the Lossy Forwarding concept in various scenarios and use cases. Finally, subsection 3.6 summarizes the simulation analysis results. Performance analysis of the RESCUE Lossy Forwarding concept developed within WP1 and WP2 in the software defined radio platform allows to draw the following conclusions. First of all, the RESCUE Lossy Forwarding technique performs always better than the baseline SDF with or without joint decoder in the destination node. In the case when the relay node is close enough to the source node to establish a lossless radio link (location A) the performance of the RESCUE LF is close to the SDF with (RESCUE) joint decoder. Lossless radio link between source and relay implicates no errors at the relay node, so in that case there is no lossy forwarding. However, an important conclusion is that RESCUE coding algorithms do not introduce loss in non-LF scenarios. On the contrary, when the distance between source and relay node is too far to establish a lossless radio link and there are errors in the relay node after decoding, the performance of the RESCUE LF is significantly better than SDF. In that case, RESCUE can be viewed as a form of estimate-and-forward relaying strategy, which is a suboptimal version of the optimal compress-and-forward strategy to be applied when successful decoding is not possible at the relay. This leads us to conclude that i) RESCUE LF performs near optimally through the whole range of relay positions and ii) RESCUE coding structure can improve performance of the SDF. Interestingly, Software defined radio platform performance analysis have shown that the gain is biggest when joint decoder in the destination node decodes jointly two copies of the transmitted frame. Sending the third and fourth copy to the destination usually does not add significant gain. This is due to the errors in the frame header, which in this case must be discarded. RESCUE D2.3 Version 1.0 Page 3 (67) In summary, the most important D2.3 contributions are the following: implementation of the RESCUE environment, which can be used by the whole GNU Radio community, presentation of the RESCUE LF concept simulation results and its performance comparison with SDF joint decoding strategy in many scenarios (QPSK, DQPSK, 16QAM, D16QAM, with and without waveform, additive white Gaussian noise (AWGN) and fading channel) feedback from practical verification to theoretical research. RESCUE D2.3 Version 1.0 Page 4 (67) Authors Partner Name Phone / Fax / e-mail AGH University of Science Jacek Wszołek jacek.wszolek@agh.edu.pl And Technology Marek Sikora sikora@kt.agh.edu.pl Jarosław Bułat jaroslaw.bulat@agh.edu.pl Krzysztof Łoziak krzysztof.loziak@agh.edu.pl Janusz Gozdecki gozdecki@agh.edu.pl Szymon Szott szott@kt.agh.edu.pl Andrzej Pach pach@kt.agh.edu.pl FQS Poland Sebastian Sośnik s.sosnik@fqs.pl Łukasz Trzeciakowski l.trzeciakowski@fqs.pl Japan Advanced Institute Xin He hexin@jaist.ac.jp of Science and Technology Shen QIAN shen.qian@jaist.ac.jp (JAIST) University of Oulu (UOULU) Valtteri Tervo valtteri.tervo@ee.oulu.fi Technical University Dresden Maximilian Matthe maximilian.matthe@ifn.et.tu-dresden.de (TUD) University of Surrey (UNIS) Jiancao Hou j.hou@surrey.ac.uk Technical University Ilmenau Christian Schneider christian.schneider@tu-ilmenau.de (TUIL) Thales Communications Hicham Khalife hicham.khalife@thalesgroup.com & Security (TCS) RESCUE D2.3 Version 1.0 Page 5 (67) Table of