Hybrid Precoding and Combining for Millimeter Wave/Sub-THz MIMO-OFDM Systems With Beam Squint Effects
Qian Wan, Jun Fang, Zhi Chen, Hongbin Li
Abstract
In this paper, we consider the problem of hybrid precoding and combining for wideband millimeter wave (mmWave) and sub-terahertz (THz) MIMO-OFDM systems with beam squint effects. In the presence of the beam squint effect, the conventional spatially sparse precoding-based hybrid precoding method which approximates the optimal precoder/combiner with a set of array response vectors suffers severe performance degradation. To address this difficulty, we propose a new set of basis vectors to approximate the optimal precoder/combiner. Each new basis vector is devised to form a radiation pattern with a wide beam to cover the squinted beam directions caused by different frequencies. Simulation results show that the proposed method can effectively alleviate the beam squint effect and achieve a substantial performance improvement over the existing state-of-the-art hybrid precoding method.