BER Based Multiuser MIMO User Selection with Block Diagonalization

It has been shown that multiuser MIMO systems have better capacity performance than single-user MIMO systems. For a large number of users, the transmitter selects a subset of users with good channels to maximize the system performance. Shannon capacity has been used most of the time as the performance measure for multiuser MIMO systems. In this paper, we consider BER as an alternative performance metric, and propose two new user selection algorithms with block diagonalization (BD), which eliminates inter-user interference in a multiuser MIMO system. The first approach is BER minimization with fixed rate, and the second approach is rate maximization with fixed target BER. Simulation results show that the proposed algorithms produce lower BER and/or higher rate when they are compared to the conventional capacity based multiuser MIMO user selection algorithm with comparable computational complexity.