An Effective Hybrid Beamforming for MIMO-OFDM with Beam Squint

Abstract

In this paper, we propose a new beamforming design method to address the effect of beam squint in Terahertz communication. Conventional schemes for mitigating the beam squint have encountered challenges, such as high power consumption due to additional complex hardware or impractical computational complexity. To overcome the limitations, we propose a new analog beamforming technique, which does not require not only a high computational complexity but also additional hardware. Specifically, our proposed scheme performs analog beamforming at symmetrically shifted frequencies using a variable ϵ to create a robust wide beamformer in frequency domain, thereby minimizing the distortion of the array gain throughout the entire bandwidth. Furthermore, the value of ϵ is expressed in a closed form based on the lower bound of achievable spectral efficiency. Our simulation results show that the proposed scheme outperforms conventional hybrid beamformer and other techniques to deal with the beam squint.