A relay selection scheme for two-way amplify-and-forward relay networks

A relay selection (RS) scheme for two-way networks with multiple amplify-and-forward relays is proposed. The scheme maximizes the worse receive signal-to-noise ratio (SNR) of the two end users. It is proved to coincide with the best-worse RS scheme originally proposed for one-way relay networks. Through rigorous error rate analysis, the scheme is shown to achieve full diversity. For networks with two relays and any power condition and constellation, an approximation on the block error rate (BLER) of the scheme is derived in closed-form. It is shown by simulation to be effective in estimating the network reliability in the high transmit power region.