Nonlinear One-Bit Precoding for Massive MIMO Downlink Systems With l₀-Norm Constraint

Using one-bit digital-to-analog converters can significantly reduce the power consumption of base station in the massive multiple-input multiple-output downlink system. In this letter, we introduce l
₀
-norm constraint on quantized transmit signals in the nonlinear one-bit precoding to further reduce the number of radio-frequency chains and thus the power consumption. This precoding is first formulated as a non-convex optimization problem, then the alternative direction method of multipliers (ADMM) is employed to solve this problem. Specifically, an efficient two-step implementation of the non-convex projection operator in ADMM is presented. Finally, the performance of proposed scheme and the effectiveness of proposed algorithm are validated by computer simulations.