Low-Complexity Constant Envelope Precoding With One-Bit DAC for Massive MU-MIMO Systems

Constant envelope (CE) precoding design problem with one-bit digital-to-analog-converters (DACs) in massive multiuser multiple-input multiple-output (MU-MIMO) has been one of core issues in fifth-generation (5G) communication technology, because CE precoding with one-bit DACs can avoid high hardware costs and high power consumption caused by a lot of radio frequency chains. In order to design the CE precoding with one-bit DACs, we need to solve a non-convex combinatorial optimization problem by jointly optimizing the precoding vector and the precoding factor. However, the corresponding optimization problem is NP-hard and difficult to solve. In this letter, we develop a linearized alternating direction method of multipliers (LADMM) algorithm to tackle the problem. Numerical experiments show that the presented LADMM algorithm gets the comparable bit error ratio (BER), faster convergence and lower complexity than the existing methods.