An improved Semi-orthogonal User Selection algorithm based on condition number for multiuser MIMO systems

In Multiple-Input Multiple-Out (MIMO) systems, the user selection algorithm plays an important role in the realization of multiplexing gain. In this paper, an improved Semi-orthogonal User Selection algorithm based on condition number is proposed. Besides, a new MIMO precoding scheme is designed. The proposed SUS-CN (SUS with condition number) algorithm outperforms the SUS algorithm for the selection of users with better matrix inversion property, thus a higher information rate for selected user pair is achieved. The designed MIMO precoding matrix brings benefits of the power equality at transmitted terminals, the limited dynamic range of the power over time, and a better power efficiency. The simulation results give the key insights into the impact of the different condition number value and users on the sum-rate capacity.