Capacity and outage performance of asynchronous Alamouti cooperative diversity

Cooperative diversity technique combined with distributed space time coding (DSTC) can efficiently improve spectral efficiency and transmission reliability of wireless communication systems. However, the time asynchronism and frequency asynchronism will destroy the structure of orthogonal DSTC, and seriously undermine the system performance. In this paper, we propose a 1×2×4 time asynchronous cooperative scheme based on distributed Alamouti code, and present a simple derivation of ergodic capacity and outage probability from the view of main eigenvalue. The simulation results show that the proposed scheme achieves a superior diversity gain and realizes multiple antennas receiving performance in time asynchronism cooperative communication system.