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Network coding designs over GF(q) spans an extensive range of research directions covering a wide range of applications. Galois field used for network coding should be a function of the total number of nodes in the networks. Thus, the larger the number of sources and relays the larger the Galois field, while keeping the same diversity order in relay-aided transmission. Furthermore, the modulation...
In this paper, we propose a distributed network coding (DNC) scheme based on the Raptor codes for wireless relay networks (WRNs), where a group of source nodes communicate with a single sink through a common relay network in a multi-hop fashion. At the sink, a graph-based Raptor code is formed on the fly. After receiving a sufficient number of encoded packets, the sink begins to decode. The main contributions...
This paper introduced a corresponding iterative decoding scheme at base station and a bitwise interleaver at the user station and relay to reduce the impact of interference and fading on the network coded cooperation in the uplink multiple-access relay systems. The authors compare the experimental performance of MARC (multiple-access relay channel) network coding over Rayleigh fading channel. The...
In this paper, we propose a novel multilevel coded linear physical-layer network coding scheme with extended mapping (LPNC-EM) for Rayleigh fading two-way relay channels (TWRC). The relay node adaptively selects the linear generator matrix and directly maps the superimposed signal of the two users into the linear network coded combination over the hybrid Galois Field (GF(22) or GF(23)). The selection...
This paper studies the four-node Multiple Access Relay Channel (MARC) under quasi-static block Rayleigh fading channels and Gaussian noise environment. A relay employs Demodulate-and-Forward (DMF) protocol in order to help two channel-encoded sources to communicate with a destination. The contributions of the paper are threefold: i) we propose a Near Optimal Joint Network/Channel decoding (NO-JNCD)...
Advanced communication techniques exploiting network coding and cooperative schemes have attracted considerable attention as ways to improve power efficiency in wireless transmission as well as to achieve high throughput and spectral efficiency. In this paper, we consider a cooperative wireless network with two nodes and one base station, and investigate the impact of the outage performance on using...
In this paper, we study the design of network codes for multi-source, multi-relay networks over frequency non-selective slow fading channels. Specifically, we consider a system with M sources each having independent information to be transmitted to a common destination with the help of N relays (called an M - N - 1 system). A finite field (nonbinary) based method is suggested to design binary network...
We present an improved decoding algorithm for joint turbo decoding and physical-layer network coding. Instead of decoding the individual (binary) messages separately at the relay, the proposed algorithm, from the superimposed faded signals, yields an XOR estimate of the sent messages. Moreover, we introduce a softening of the XOR values to improve the overall performance. Simulation results show that...
In this paper, we study the performance of network-coded cooperative wireless networks with channel coding over each wireless links. As a case study, the two-source two-relay network is considered and the performance vs. energy-efficiency trade-off of various network code designs (offering both equal and unequal error protection capabilities) over fast- and slowly-varying fading channels is studied...
In this paper, we study the three-node multiple-access relay channel under realistic operating conditions. More specifically, in our setup all wireless links are subjected to Rayleigh fading and Gaussian noise, and the relay node can be located at different distances from source and destination nodes. We assume that coded bits are fully-interleaved, so that the transmitted symbols are mutually independent...
In this paper, we propose a simple analytical methodology to study the performance of multi-source multi-relay cooperative wireless networks with network coding at the relay nodes and Maximum-Likelihood (ML-) optimum channel-aware detectors at the destination. Channel-aware detectors are a broad class of receivers that account for possible decoding errors at the relays, and, thus, are inherently designed...
In this paper we present a decentralized, energy efficient strategy called partial network coding with cooperation (PNC-COOP) for multi-hop wireless communication. It is a cross-layer design that combines opportunistic network coding and decode-and-forward cooperative diversity. By applying the proposed technique to the nodes in the network based on the opportunity provided, the saving of transmitted...
We study the design of network codes for M-source, N-relay wireless networks over slow fading channels. Specifically, vector-wise binary field network coding (BFNC) schemes are proposed. In the construction of our BFNC schemes, we utilize a diversity achieving criterion which can be expressed in terms of the linear independence of quasi-cyclic matrices. Our codes can be implemented with low-complexity...
In this paper, we investigate joint network and channel decoding algorithms for the multiple-access relay channel. We consider a realistic reference scenario with Rayleigh fading over all the wireless links, including the source-to-relay channels. Our contribution is twofold: i) first, we develop the quasi-optimal joint network and channel decoder by taking into account possible errors over the source-to-relay...
In this paper a physical-layer network coded two-way relay system applying Low-Density Parity-Check (LDPC) codes for error correction is considered, where two sources A and B desire to exchange information with each other by the help of a relay R. The critical process in such a system is the calculation of the network-coded transmit word at the relay on basis of the superimposed channel-coded words...
In this paper, we propose a Decode-and-Forward Network Coded (DFNC) multi-user cooperation scheme for orthogonal uplink channels in a wireless network. The network consists of m peers having independent information transmitting to a common destination. Each peer transmits its own data in the first time phase and serves as a relay in the second time phase to transmit the network coded information combining...
In this paper, we investigate the benefit of joint network-channel (JNC) coding for the multiple-access full-duplex relay channel. We use superposition block Markov network-channel (distributed) coding and (iterative) joint decoding at the destination. Prominent amongst our system assumptions are the fact that the medium access is not orthogonal and that the source-to-relay links are not error-free,...
This paper studies a network coding scheme that exploits a cooperative diversity and adaptation to variant link states for reliable networks. We propose a scheme, adaptive rate network coding (ARNC), to change the number of transmission in relay nodes according to channel states over fading channels by matching network graphs with rateless code graphs, raptor codes. In ARNC scheme, a relay transmits...
This paper provides the practical design of the transmit diversity technique with a nested coding technique and evaluates its performance via computer simulations. Similar to network coding techniques, the nested transmit diversity combines the transmit data with XOR operation. As a characteristic of the proposed transmit diversity, it can obtain diversity gain without some extra resources (e.g.,...
Network coding was proposed to increase the achievable throughput of multicast in a network. Recently, combining network coding into user cooperation has attracted research attention. For cooperative transmission schemes with network coding, users combine their own and their partner's messages by network coding operation. In previous works, it was shown that adaptive DF with network coding can achieve...
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