Low-Complexity DOA Estimation of Wideband Signals Based on Intelligent Optimization Algorithms in Massive MIMO Systems

Direction-of-arrival (DOA) estimation is crucial for channel state information (CSI) estimation in massive multiple-input multiple-output (MIMO) systems. However, traditional narrowband DOA estimation methods are unsuitable for wideband signals whose bandwidth continuously increase with the transmission rate of the communication systems. In this paper, we propose a low-complexity DOA estimation algorithm based on intelligent optimization algorithms for wideband signals in massive MIMO systems. First, a real-value wideband DOA estimation method is proposed to reduce the computational complexity. To further improve spectral peak search efficiency, we propose an intelligent spectral peak searching algorithm, which uses genetic algorithm (GA) to optimize the angle search process to obtain DOA. Furthermore, to reduce the problem of multiple parameter settings in GA algorithm, we propose to use the particle swarm optimization algorithm (PSO) to optimize the peak search. Simulation results indicate that the proposed algorithms can effectively estimate the angle of wideband sources in massive MIMO systems and outperform some existing methods in complexity.