Decode-and-forward cooperation as the distributed encoding and decoding

The decode-and-forward relaying is studied as two problems of the distributed encoding and decoding. Specifically, in the first problem, the source and the relay employ the same channel encoding, and the objective is to find how to distribute the decoding complexity between the relay and the destination. The objective of the second problem is to distribute the encoding complexity between the source and the relay while using any type of the channel decoding at the relay and at the destination. Extensive simulation results are obtained assuming binary linear block coding of short block length, binary modulation, fast Rayleigh fading, and various relay locations are modeled as the propagation path-loss. The order statistics decoding is adopted due to its excellent flexibility to trade-off the decoding complexity and the bit error rate performance. It is found that the decoding complexity distribution is strongly relay location dependent, and, for the case without the path-loss, the distribution of the minimum Hamming distances of the channel encodings is more important than the distribution of the code rates.