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Outage probability bound of decode and forward two-way relay employing optical spatial modulation over gamma-gamma channels

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IET OPTOELECTRONICS 2019年第4期13卷 183-190页

作者： Bhowal, Anirban Kshetrimayum, Rakhesh Singh Indian Inst Technol Dept Elect & Elect Engn Gauhati Assam India

In this study, free space optical communication has been studied for different atmospheric conditions. Spatial modulation (SM) has been used to improve the performance of two-way relay cooperative communication. The proposed system employs decode and forward (DF) relaying technique along with physical layer network coding, hence it has been named as optical SM based DF two-way relay. It enables full-duplex communication thereby enhancing the system efficiency. The transmit optical source index as well as the information are exchanged between the two bidirectional nodes. Performance analysis of the system has been carried out in terms of lower and upper bounds of outage probability and average data rate for N-gamma cascaded fading channels. The analytical results have been validated by means of Monte Carlo simulations. The variation of the performance due to change in different parameters has also been reported in this study.

关键词： optical modulation network coding cooperative communication fading channels Monte Carlo methods probability decode and forward communication relay networks (telecommunication) telecommunication network reliability free-space optical communication free space optical communication physical layer network coding optical SM full-duplex communication outage probability optical spatial modulation gamma-gamma channels atmospheric conditions DF relaying technique optical source index decode and forward two-way relay two-way relay cooperative communication bidirectional nodes N-gamma cascaded fading channels Monte Carlo simulations

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Multi-channel Tracking with Different Fading Rates in an OFDM-PLNC network

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WIRELESS PERSONAL COMMUNICATIONS 2018年第1期98卷 1015-1028页

作者： Khosroazad, Somayeh Neda, Naaser Univ Birjand Fac Elect & Comp Engn Birjand Iran

In this paper, we address the problem of tracking the time varying/frequency selective fading channels with different fading rates in a decode-and-forward physical layer network coding (PLNC) structure. Since, in a PLNC system multi users send their information to the relay, simultaneously, the relay needs to estimate the uplink multi-channels, simultaneously, to be able to extract the network coded signal from superimposed signals. Different fading rates of channels due to different velocities of mobile users in a PLNC system make the channel tracking problem more complex. Providing an algorithm to simultaneous track multi-channels in such a system is the main object of this paper. To this end, a time domain channel tracking algorithm based on sum-product rules is derived, where, both frequency and time selectivity characteristics of the channels are taken into account. In order to stabilize against the frequency selectivity property of the channels, orthogonal frequency division multiplexing is also considered in this system. High accuracy, no phase ambiguity, and stability in fast fading conditions are some advantages of the proposed approach. The performance of the algorithm in the existence of channel coding has been also considered and compared with the non-coded channel system.

关键词： physical layer network coding Orthogonal frequency division multiplexing (OFDM) Channel tracking Sum-product algorithm Factor graph

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Compressed Video Streaming in Cooperative Wireless networks with Interfering Transmissions

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IEEE TRANSACTIONS ON COMMUNICATIONS 2012年第11期60卷 3407-3416页

作者： Argyriou, Antonios Univ Thessaly Dept Comp & Commun Engn Volos 38221 Greece

In this paper, we present a video streaming system for wireless networks that employs utility optimization of pre-compressed video at the application layer, together with a novel cooperative wireless physical layer (PHY) that allows interfering transmissions. Our system model considers multiple and independent unicast or multicast transmissions between network nodes while a number of them serve as relays. For this new PHY the average transmission rate that each sender-destination pair can achieve is estimated first. Next, we show that the utility optimization problem can be simplified due to the features of the proposed PHY. Subsequently, we devise a utility optimization algorithm that is executed independently at each sender and it derives the optimal video packets that should be sent in the wireless link given the calculated rate constraint. Simulation results demonstrate that for unicast video streaming scenarios and with the utility optimization framework, allowing packets to interfere is a better choice than employing a typical cooperative PHY. For the case of multicast video delivery the performance of the proposed scheme is significantly improved for good channel conditions while the improvement is minimized in the low channel SNR regime when compared to the unicast scenario.

关键词： Video streaming wireless networks interference cooperative systems physical layer network coding

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Pairwise Check Decoding for LDPC Coded Two-Way Relay Block Fading Channels

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IEEE TRANSACTIONS ON COMMUNICATIONS 2012年第8期60卷 2065-2076页

作者： Liu, Jianquan Tao, Meixia Xu, Youyun Shanghai Jiao Tong Univ Dept Elect Engn Shanghai 200240 Peoples R China PLA Univ Sci & Technol Inst Commun Engn Nanjing 210007 Jiangsu Peoples R China

Partial decoding has the potential to achieve a larger capacity region than full decoding in two-way relay (TWR) channels. Existing partial decoding realizations are however designed for Gaussian channels and with a static physical layer network coding (PLNC). In this paper, we propose a new solution for joint network coding and channel decoding at the relay, called pairwise check decoding (PCD), for low-density parity-check (LDPC) coded TWR system over block fading channels. The main idea is to form a check relationship table (check-relation-tab) for the superimposed LDPC coded packet pair in the multiple access (MA) phase in conjunction with an adaptive PLNC mapping in the broadcast (BC) phase. Using PCD, we then present a partial decoding method, two-stage closest-neighbor clustering with PCD (TS-CNC-PCD), with the aim of minimizing the worst pairwise error probability. Moreover, we propose the minimum correlation optimization (MCO) for selecting the better check-relation-tabs. Simulation results confirm that the proposed TS-CNC-PCD offers a sizable gain over the conventional XOR with belief propagation (BP) in fading channels.

关键词： Two-way relaying block fading channel LDPC physical layer network coding partial decoding pairwise check decoding closest-neighbor clustering

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The Resilience of Massive MIMO PNC to Jamming Attacks in Vehicular networks

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IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS 2021年第7期22卷 4110-4117页

作者： Okyere, Bismark Musavian, Leila Ozbek, Berna Busari, Sherif A. Gonzalez, Jonathan Univ Essex Sch Comp Sci & Elect Engn Colchester CO4 35Q Essex England Izmir Inst Technol Elect Elect Engn Dept TR-35430 Izmir Turkey GS Lda Agueda 3750101 Portugal

In this article, we investigate the resilience of Massive MIMO physical layer network coding (PNC) to jamming attack in both sub-6 GHz and millimeter-Wave (mmWave) systems in vehicular networks. Massive MIMO generally is resilient to jamming attacks, and we investigate the impact that PNC has on this resilience, if combined with Massive MIMO. The combination of Massive MIMO and PNC has shown a significant improvement in the bit error rate (BER) in our previous investigation. The corresponding framework is analysed against a barraging attack from a jammer, where the jamming channel is not known to the base station (BS), and the jammer can use any number of transmit antennas. Over Rayleigh channel, our simulation results reveal that Massive MIMO PNC performs better in the lower signal-to-noise ratio (SNR) regions to jamming attacks and this is achieved at twice the spectral efficiency. A similar performance is observed over mmWave channel.

关键词： Massive MIMO physical layer network coding vehicular networks jamming

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Wireless network-Coded Bidirectional Relaying Using Latin Squares for M-PSK Modulation

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IEEE TRANSACTIONS ON INFORMATION THEORY 2013年第10期59卷 6683-6711页

作者： Muralidharan, Vijayvaradharaj Tirucherai Namboodiri, Vishnu Rajan, B. Sundar Indian Inst Sci Dept Elect Commun Engn Bangalore 560012 Karnataka India

The design of modulation schemes for the physical layer network-coded two-way relaying scenario is considered with a protocol which employs two phases: multiple access (MA) phase and broadcast (BC) phase. It was observed by Koike-Akino et al. that adaptively changing the network coding map used at the relay according to the channel conditions greatly reduces the impact of MA interference which occurs at the relay during the MA phase and all these network coding maps should satisfy a requirement called the exclusive law. We show that every network coding map that satisfies the exclusive law is representable by a Latin Square and conversely, that this relationship can be used to get the network coding maps satisfying the exclusive law. The channel fade states for which the minimum distance of the effective constellation at the relay become zero are referred to as the singular fade states. For M - PSK modulation (M any power of 2), it is shown that there are (M-2/4 - M/2 + 1) M singular fade states. Also, it is shown that the constraints which the network coding maps should satisfy so that the harmful effects of the singular fade states are removed, can be viewed equivalently as partially filled Latin Squares (PFLS). The problem of finding all the required maps is reduced to finding a small set of maps for M - PSK constellations (any power of 2), obtained by the completion of PFLS. Even though the completability of M x M PFLS using M symbols is an open problem, specific cases where such a completion is always possible are identified and explicit construction procedures are provided. Having obtained the network coding maps, the set of all possible channel realizations (the complex plane) is quantized into a finite number of regions, with a specific network coding map chosen in a particular region. It is shown that the complex plane can be partitioned into two regions: a region in which any network coding map which satisfies the exclusive law gives the same best performa

关键词： Latin squares physical layer network coding wireless bidirectional relaying

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Data sharing among wireless client devices in cooperative manner with minimum transmissions

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JOURNAL OF AMBIENT INTELLIGENCE AND HUMANIZED COMPUTING 2019年第9期10卷 3329-3338页

作者： Lin, Nyan Kurkoski, Brian M. Tan, Yasuo Lim, Yuto Japan Adv Inst Sci & Technol 1-1 Asahidai Nomi Ishikawa 9231292 Japan

A group of nearby wireless end devices such as mobile phones can benefit a fast service to satisfy their required packets by cooperating to exchange their packets after receiving collectively from a common base station. This problem can be formulated as a coding and transmission scheme and solved by the linear network coding. We propose a balanced coding and transmission (BCT) scheme that assigns suitable clients to find and transmit linear combinations of the received packets. The goals of our scheme are to minimize the total number of transmissions, to maintain fairness on the number of transmissions among the participants in the cooperative group and to maintain the limited energy resources until all members satisfy their needs. Moreover, we also introduce transmission scheme with physical layer network coding (BCTS/PNC) for the same problem to further reduce the required transmission time slots and accomplish the data exchange process in short time. We present the performance of the schemes and discussion in terms of the fairness, the number of transmissions and the completion time by testing with various simulation parameters and scenarios.

关键词： Cooperative data exchange Linear combination physical layer network coding Wireless multi-hop networks Fairness

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Single and Dual Relay Selection in Two-Way network-coded Relay networks

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WIRELESS PERSONAL COMMUNICATIONS 2015年第1期83卷 99-115页

作者： Razmi, Nasrin Attari, Mahmoud Ahmadian Soleimani-Nasab, Ehsan Ghasemi, Abdorasoul KN Toosi Univ Technol Fac Elect & Comp Engn Tehran Iran Grad Univ Adv Technol Fac Elect & Comp Engn Kerman Iran

In this paper, the relay selection problem for two-way relaying networks in single and dual relay selection schemes is addressed. In the single relay selection scheme, the problem is to find the best relay node which leads to the minimum bit error rate (BER) between the source nodes. We then derive the upper and lower bounds for the signal to noise ratio and the end-to-end BER of this scheme. In the dual relay selection scheme, the problem is to find the two best relay nodes. In this scheme, Alamouti space-time coding and physical layer network coding are utilized in order to achieve the higher performance. For improving the system performance, optimal power allocation between the sources and the relays is considered based on decreasing the BER. Finally, simulation results are provided to verify the correctness of analytical results.

关键词： Alamouti space-time coding Bit error rate Dual relay selection physical layer network coding Single relay selection

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Joint Beamforming Optimization and Power Control for Full-Duplex MIMO Two-Way Relay Channel

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2015年第3期63卷 555-566页

作者： Zheng, Gan Univ Essex Sch Comp Sci & Elect Engn Colchester CO4 3SQ Essex England Univ Luxembourg Interdisciplinary Ctr Secur Reliabil & Trust SnT Luxembourg Luxembourg

In this paper, we explore the use of full-duplex radio to improve the spectrum efficiency in a two-way relay channel where two sources exchange information through an multi-antenna relay, and all nodes work in the full-duplex mode. The full-duplex operation can reduce the overall communication to only one phase but suffers from the self-interference. Instead of purely suppressing the self-interference, we aim to maximize the end-to-end performance by jointly optimizing the beamforming matrix at the relay which uses the amplify-and-forward protocol as well as the power control at the sources. To be specific, we propose iterative algorithms and 1-D search to solve two problems: finding the achievable rate region and maximizing the sum rate. At each iteration, either the analytical solution or convex formulation is obtained. We compare the proposed full-duplex two-way relaying with the conventional half-duplex two-way relaying, a full-duplex one-way relaying and a performance upper bound. Numerical results show that the proposed full-duplex scheme significantly improves the achievable data rates over the conventional scheme.

关键词： Beamforming full-duplex radios optimization physical layer network coding two-way relay channel

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Distributed Space Time coding for Wireless Two-Way Relaying

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2013年第4期61卷 980-991页

作者： Muralidharan, Vijayvaradharaj T. Rajan, B. Sundar Indian Inst Sci Dept Elect Commun Engn Bangalore 560012 Karnataka India

We consider the wireless two-way relay channel, in which two-way data transfer takes place between the end nodes with the help of a relay. For the Denoise-And-Forward (DNF) protocol, it was shown by Koike-Akino et al. that adaptively changing the network coding map used at the relay greatly reduces the impact of Multiple Access Interference at the relay. The harmful effect of the deep channel fade conditions can be effectively mitigated by proper choice of these network coding maps at the relay. Alternatively, in this paper we propose a Distributed Space Time coding (DSTC) scheme, which effectively removes most of the deep fade channel conditions at the transmitting nodes itself without any CSIT and without any need to adaptively change the network coding map used at the relay. It is shown that the deep fades occur when the channel fade coefficient vector falls in a finite number of vector subspaces of, which are referred to as the singular fade subspaces. DSTC design criterion referred to as the singularity minimization criterion under which the number of such vector subspaces are minimized is obtained. Also, a criterion to maximize the coding gain of the DSTC is obtained. Explicit low decoding complexity DSTC designs which satisfy the singularity minimization criterion and maximize the coding gain for QAM and PSK signal sets are provided. Simulation results show that at high Signal to Noise Ratio, the DSTC scheme provides large gains when compared to the conventional Exclusive OR network code and performs better than the adaptive network coding scheme.

关键词： Distributed space time coding physical layer network coding wireless two-way relaying

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