Output-Threshold Multiple-Relay-Selection Scheme for Cooperative Wireless Networks

An output-threshold multiple-relay-selection (OT-MRS) scheme for dual-hop multibranch cooperative wireless networks is proposed. In this scheme, the first Lc (nonordered) relays are sequentially selected out of L relays such that the SNR of the maximal ratio combined Lc relayed paths and the direct path exceeds a preset threshold. Analytical results for the performance bounds are derived. The numerical results verify the analyses and show that OT-MRS outperforms optimal single-relay selection and generalized-selection-combining-based multiple relay-selection for low to moderately high SNRs. The proposed scheme provides more flexibility in utilizing bandwidth and spatial diversity in cooperative wireless networks.