A suboptimal user selection algorithm for multiuser MIMO systems based on block diagonalization

In this paper, we propose a suboptimal user selection algorithm based on block diagonalization (BD) with low complexity. An upper-bound of sum-rate capacity is deduced. And considering it as the selection criterion we get our proposed algorithm. Furthermore in simplification of the proposed algorithm it is regarded as the adaptive criterion instead of capacity formula. After that we analyze the computational complexity in detail, and then compare the proposed algorithm with optimal selection algorithm and maximum norm selection method. Simulation results show that the proposed algorithm and its simplification can achieve the same sum-rate capacity as the optimal exhaustive search method in lower SNR, and in higher SNR they are both very close to the performance of optimal method.