All-participate hybrid forward cooperative communications with multiple relays

Cooperative communication significantly improves system performance and capacity by transmitting the same information through relays. In this paper, we generalize the idea of hybrid decode-and-forward (DF)/amplify-and-forward (AF) schemes for single relay to the multiple relays scenario and refer to it as the all-participate hybrid forward (APHF) scheme. In the APHF scheme, each relay adaptively chooses, on a frame basis, between AF and DF schemes by examining the cyclic redundancy check (CRC) result. To analyze the frame error rate (FER) of the proposed scheme, we provide a signal-to-noise-ratio (SNR) threshold-based FER approximation model, which is simple and accurate for general diversity systems. With this FER approximation model, we derive a closed-form FER expression and a simplified FER expression at high SNR for the APHF scheme. The analytical results are verified through simulation.