Slotted Cooperative Communication in Half Duplex Relay Networks

In cooperative communication systems, different terminals collaborate to form a virtual-multiple antenna array system and exploit the spatial diversity to achieve a better performance. It can be generally categorized into amplify-andforward protocol and decode and-forward protocol. Among the various cooperative communication protocols which have been proposed in the past decades, the slotted cooperation protocol demonstrated superior diversity multiplexing tradeoff (DMT) performance in achieving the multiple-input single-output (MISO) bound in a half duplex relaying network. The first objective of this study is to investigate the performance of the slotted cooperation in a half-duplex distributed space-time coding (DSTC) network. First, we investigate the performance of slotted cooperation in DSTC network and evaluate the performance in terms of pairwise error probability (PEP) and bit error rate (BER). We show that the proposed Slotted-DSTC protocol increases the symbol rate by 100% and have the same bit-error rate performance compared to the traditional DSTC protocol. We further extend the proposed Slotted-DSTC to Slotted-DSTC with redundant codes (Slotted-DSTC-R) protocol, where the source is transmitting the same frame of space-time coded signals to two relay clusters over two consecutive time frames. We show that the Slotted-DSTC-R protocol reduces the decoding complexity by 20 − 30% while maintaining the same achievable diversity order. On the other hand, the proposed protocol also reduces the minimum coherence interval requirement by 50% when compared to the orthogonal-DSTC protocol.