Multi-Branch Vector Perturbation Precoding Design Using Lattice Reduction for MU-MIMO Systems

This paper investigates the design of vector perturbation (VP) precoding using lattice reduction (LR) based on a multi-branch (MB) strategy for multi-user multiple-input multiple-output (MU-MIMO) systems. The MB strategy constructs a group of branches for transmitting data streams according to a pre-designed ordering scheme. For each branch, an LR-aided minimum mean square error (MMSE) VP precoder is proposed and three methods are devised for the perturbation vector design. We also develop an effective scheme to design the transmit ordering patterns with appropriate structures and a suitable selection mechanism to choose the best one. Simulation results show that the proposed MB-LR-MMSE-VP algorithm achieves a better bit error rate (BER) performance than existing VP precoding schemes.