Relay Selection in Distributed Transmission Based on the Golden Code in Wireless Networks

The implementation of cooperative diversity with relays has advantages over point-to-point multiple-input multipleoutput (MIMO) systems in particular overcoming correlated paths due to small inter-element spacing. A simple transmitter with one antenna may moreover exploit cooperative diversity or space time coding gain through distributed relays. In this paper, similar distributed transmission is considered with the golden code, and we propose a new strategy for relay selection, called the maximum-mean selection policy, for distributed transmission based on a wireless relay network. This new strategy performs a channel strength tradeoff at every relay node to select the best two relays for transmission. It improves upon the established onesided selection strategy of maximum-minimum policy. Simulation results comparing the bit error rate (BER) of a scheme without relay selection, with the maximum-minimum and maximummean selection schemes confirm the performance advantage of relay selection and that our proposed strategy yields the best performance of the three methods.