Channel coded complex field network coding in two-way relay networks

This paper investigates the implementation of complex field network coding (CFNC) technique in two-way relay networks. The application of convolutional channel codes with two different decoding schemes is also studied in the given setup. Two source nodes use the same convolutional code and both decoding schemes are based on Viterbi algorithm (VA). The first decoding method combines trellis structures of the convolutional codes, employed at both sources, and utilizes VA for decoding at relay. Since this method has high complexity, a second method with reduced complexity is suggested. The second method performs a sub-optimal decoding metric calculation followed by a disjoint channel decoding for the two sources. Bit error ratio simulations are performed for both decoding schemes in Rayleigh and Nakagami-m fading environments. Simulation results indicate that the reduced complexity decoding provides the same diversity gain as the joint full state decoding with negligible loss in performance.