Differential Multiply-and-Forward and Selective Combining Based Multi-relay TDBC Protocol

In this paper, we propose a differential multiplyand-forward (DMF) and selective combining (SC) based multirelay time division broadcasting (TDBC) protocol, named as DMF-SC, in rayleigh fading channels. Different from amplify and-forward relaying (AF) and decode-and-forward (DF) relaying, in DMF multi-relaying, each relay broadcasts the product of two signals received from two terminals. The decision variables from the direct and cascaded links at the terminal node are selective combined to obtain the cooperative diversity. Theoretical analyses and simulation results show that the proposed DMFSC protocol can obtain a order N + 1 cooperative diversity, and outperforms AF, DF and multiplicative network coding protocols with differential modulation. Meanwhile, no channel state information is needed at the terminals with the proposed DMF-SC based multi-relay TDBC protocol.