Equiphase Precoder Design for Cooperative Communication with Complex Field Network Coding

Complex field network coding (CFNC) can be employed to achieve ideal throughput as high as 1/2 symbol per source per time slot (sym/S/TS) in relay-based cooperative communications. In this paper, equiphase precoder (EP) scheme for CFNC-based system (EP-CFNC) is proposed to achieve better symbol error probability (SEP) performance. The distribution of transmitted symbol´s constellation is carefully designed against noise. The theoretical analysis provides a method to estimate the SEP and verifies the coding gain obtained by equiphase precoder. Moreover, simulation results, in both additive complex White Gaussian noise (AWGN) channels and Rayleigh fading channels, show that SEP can be substantially reduced via the proposed EP-CFNC algorithm.