Full Rate and Full Diversity STBC in Decode-and-Forward Relay Systems

Diversity techniques are very effective tools to increase signal reception quality in Rayleigh fading channels. A novel space-time block coding method for cooperative relay networks is proposed which guarantees full diversity for any number of mobile relays with minimal delay, provided that few bits of feedback from the destination to the source and the relays are available. As in the case of orthogonal space-time block codes, all transmitted symbols are separately decoded both in the relays and the destination. Therefore, decoding complexity is linear. In our proposed scheme, larger number of codes can be generated for improved coding gain. The performance of the proposed scheme is investigated for cooperative communication. It is shown that the new approach provides SNR improvement, and it is more resilient to feedback errors compared to the antenna selection technique on the basis of same number of feedback bits.