Efficient Constant Envelope Precoding for Massive MU-MIMO with 1-Bit DAC

Massive multiuser multiple-input multiple-output (MU-MIMO) is a cornerstone of 5G technology, offering significant gains in data rate and network capacity. However, its deployment is challenged by the high energy consumption and hardware costs of large antenna arrays at base stations. The use of 1-bit constant envelope (CE) precoding has emerged as an effective solution to reduce both power consumption and hardware complexity. Designing 1-bit CE precoding involves a non-convex combinatorial optimization problem with tightly coupled variables, which is computationally challenging. This paper proposes a novel algorithm based on the alternating direction method of multipliers (ADMM) and the heavy-ball (HB) method to efficiently solve this problem. Our approach provides an exact solution with notably lower computational complexity. Simulations demonstrate that the proposed algorithm outperforms existing schemes, achieving improved bit error rate (BER) and faster convergence.