Linear Precoding Techniques for 2-Hop MIMO Relaying

In this paper, we deal with the linear precoding techniques for 2-hop multiple-input multiple-output (MIMO) relaying, where limited feedback is available at source and relay nodes. Among the various linear precoding schemes, we utilize quantized precoding technique which is more implementable than precoding schemes with full feedback due to short feedback length. Based on quantized precoding technique, we propose the source and relay precoding matrix selection criterion in the given codebook to improve the bit error rate (BER) performance. As a results, the performance of the proposed algorithm exceeds than that of open-loop MIMO relaying using optimum maximum likelihood (ML) receiver and Alamouti’s scheme which is optimum open-loop orthogonal space-time block coding (OSTBC). Moreover, simulation results show that the proposed scheme has more diversity gain comparing with other open-loop schemes.