An Improved Norm-Based User Selection Algorithm for Multiuser MIMO Systems with Block Diagonalization

This paper presents an improved norm-based user selection algorithm for multiuser MIMO systems with block diagonalization. Our motivation is to reduce the complexity of the original norm-based algorithm while keeping the throughput performance. The main ideas consist of applying a heuristic Gram-Schmidt orthogonalization in the design of precoding matrix and constructing a user-reduced set that is semiorthogonal to the already selected users in each iteration. Numerical examples demonstrate the effectiveness of our proposed algorithm. The low computational complexity makes it very suitable for implementation in a practical system.