A Novel Distributed Space-Time Block Coding Protocol for Cooperative Wireless Relay Networks

Wireless relay has recently gained a lot of interest in the research community. It was suggested to use space-time block codes in the cooperative relaying system to increase the spectral efficiency of the relaying protocol. Using space-time codes in the relaying scheme also provides the diversity benefits of multiple antenna techniques. In this paper, a new method of distributed space-time coding based on Alamouti codes with one regenerative relay called "on-channel distributed space-time block coding" is introduced and analyzed. By a slight modification in the proposed scheme, "recursive on-channel relaying" technique is proposed which is shown to have better performance. After showing theoretically that the proposed methods achieve spatial diversity gain, performance of them is then evaluated via Monte-Carlo simulation. It is shown that the proposed space-time coded relaying protocols perform better in moderate to high SNR, compared to repetition-based relaying protocols, and requires 3 dB less SNR to achieve a BER of 10^-4.