Diversity Analysis of Coded Beamforming in MIMO-OFDM Amplify-and-Forward Relaying Systems

In this letter, we investigate the diversity performance of coded beamforming schemes in AF multiple antenna relay systems for frequency selective channels. To extract available multipath diversity, we utilize orthogonal frequency division multiplexing combined with bit-interleaved coded modulation. The pairwise error probability is analyzed based on the correlated fading assumption, and the theoretical evaluation of the maximum achievable diversity order is presented. From the analysis, a proper code construction criterion is provided which achieves the full diversity with the minimum code memory. Our analysis also demonstrates that the subcarrier mapping (or pairing) operations at the relay have no impact on the diversity order. Simulations confirm that our analysis is accurate and matches well with the simulation results.