Cooperative Diversity over Log-Normal Fading Channels

In this paper, we investigate the performance of cooperative diversity schemes over log-normal fading channels which provide an accurate channel model for indoor wireless environments. We focus on single-relay cooperative networks with amplify-and-forward relaying and consider three TDMA-based cooperation protocols which correspond to distributed implementations of MIMO (multi-input multi-output), SIMO (single-input multi-output), and MISO (multi-input single-output) schemes. For each protocol under consideration, we derive pairwise error probability expressions over log-normal channels and quantify the diversity advantages. Based on the minimization of a union bound on the bit error rate performance, we further formulate optimal power allocation schemes which demonstrate significant performance gains over their counterparts with equal power allocation.