An Effective transmit Weight Design for DPC with Maximum Beam in Multi-user MIMO Downlink

摘要

A novel transmit scheme is proposed for the cancelation of Inter-User Interference (IUI) and the improvement of achievable sum-rate of system in Multi-User Multiple-Input Multiple Output (MU-MIMO) downlinks. Particle Swarm Optimization (PSO) algorithm is employed to solve the constrained nonlinear optimization problem for obtaining the optimal transmit weights. Compared with the conventional Dirty Paper Coding (DPC) having single receive antenna, the proposed scheme applies the principle of DPC to cancel the IUI in MU-MIMO downlinks, where the Mobile Station (MS) users are equipped with multiple receive antennas. With the Channel State Information (CSI) known at the Base Station (BS) and the MS, the eigenvalues for all user channels are calculated first and then the user with the maximum eigenvalue is selected as the 1-st user. For the remaining users, the users are sequentially processed and the transmit weights are generated from the previously selected users by using the Particle Swarm Optimization (PSO) algorithm, which makes the transmit gain for each user as large as possible. The analysis of computa-tional load and simulation results verify the effectiveness of the proposed scheme.