Joint Partial Relay Selection, Power Allocation and Cooperative Maximum Likelihood Detection for MIMO Relay Systems with Limited Feedback

In this paper, joint partial relay selection (PRS) and power allocation methods are proposed in conjunction with cooperative maximum likelihood (ML) detectors. These methods are considered for selecting relay nodes that improve the bit error rate (BER) performance of a two-phase multiple-input multiple-output (MIMO) half-duplex decode-and-forward (DF) relay system with log-normal shadowing and power constraints, as compared to using all relays available regardless of whether the additional relays will benefit the system. Limited feedback is applied to the joint PRS and power allocation techniques within the system, with results showing the effects of the proposed relay selection methods on BER performance.