Multiuser XOR-and-forward relaying using Alamouti STBC

In this paper we propose a multiuser two-way relaying scheme using an XOR-and-forward strategy with space-time block coding (STBC). In this scheme, all users transmit their symbols simultaneously to the relay in the first phase. The relay uses minimum mean square error detection to estimate the transmitted symbols, and then it uses an XOR operation to combine the estimates of the symbols for each user pair and broadcasts them in the second phase. The bit error rate performance and the outage capacity for the proposed scheme is evaluated numerically in an uncorrelated flat fading channel. The simulation results show that the scheme can improve the throughput and the channel reliability.