Space-time code ARQ protocol for wireless networks

Multiuser cooperative communication is a novel transmission technique, where the antennas on adjacent mobile terminals are formed as a virtual antenna array (VAA) to realize spatial diversity gain in a distributed way. A space-time code ARQ protocol exploiting the cooperation capability between nodes in wireless networks is proposed in this paper. Different to the traditional ARQ protocol, the erroneously received packet is retransmitted by the source terminal and a relay terminal simultaneously using space-time code, which results in the realization of transmit diversity. The packet error rate (PER) performance of space-time code ARQ is derived in both correlated and uncorrelated block fading wireless channels, in comparison with the traditional ARQ. Our analysis shows that the space-time code ARQ is capable of extracting second-order diversity and third-order diversity in correlated and uncorrelated block fading channels, respectively, while the traditional ARQ only achieves first-order diversity and second-order diversity, correspondingly.