A Practical Network Coding Scheme over GF(2q) for Multi-User Cooperative Communication

Network coding has been proved to provide significant performance improvement for cooperative communication systems. In this paper, we present a Decode-and-Forward Network Coded (DFNC) scheme over GF(2^q) for multi-user cooperative communication system. In particular, we propose an efficient coding coefficients construction method so as to reduce the transmission overhead from m(q+log₂ {m}) to m bits compared with conventional random network coding. Moreover, we propose a novel decoding algorithm-Credit-based Updating Algorithm (CUA), which is combined with channel decoding and works on symbol-level, in order to improve the solvability of decoding set of equations in the destination and fully make use of the advantages from network coding while conventional decoding algorithms (e.g., Gaussian Elimination) ignore it. In this manner, the proposed decoding algorithm helps fully exploit the spatial diversity and redundancy residing in network coding. From the simulation results, we show that DFNC outperforms other transmission schemes in terms of SER and achieves higher diversity order. We also demonstrate that the proposed decoding algorithm provides significant performance gain over conventional decoding algorithm.