Dual Orthogonal Projections for Multiuser Interference Cancellation in mmWave Beamforming With Uniform Planar Arrays

TL;DR

This paper introduces an iterative dual orthogonal projection algorithm for multiuser interference cancellation in mmWave beamforming, achieving near-optimal spectral efficiency with low complexity and applicability to various architectures.

Contribution

The paper proposes a novel iterative DOP algorithm that effectively cancels MUI in mmWave systems, converging rapidly to theoretical limits and extending to different beamforming architectures.

Findings

Spectral efficiency approaches DPC performance with each iteration.

DOP outperforms existing linear interference cancellation methods.

Algorithm is applicable to both fully-digital and hybrid beamforming systems.

Abstract

This paper investigates multiuser interference (MUI) cancellation for millimeter-wave (mmWave) beamforming in communication systems. We propose a linear algorithm, termed iterative dual orthogonal projections (DOP), which alternates between two orthogonal projections: one to eliminate MUI and the other to refine combiners, ensuring empirical convergence in spectral efficiency. Simulation results show that, with each iteration, the spectral efficiency of each user converges rapidly, closely approaching the theoretical optimum determined by dirty paper coding (DPC), surpassing existing linear benchmarks while maintaining low computational complexity. Furthermore, the proposed DOP algorithm is extended to support both fully-digital and hybrid beamforming architectures.