An Efficient Beamforming Design for Near-Field Beam Squint Mitigation in Wideband ELAA Systems.

In the future 6G wireless networks, the growing number of antennas and extra-wide mmWave frequency band will lead to near-field effect and beam squint effect. The generated beams at different frequencies will respectively focused at different locations referred to as the near-field beam squint effect, which will cause a severe performance degradation, remaining to be mitigated efficiently to enhance the data rates. We propose an efficient grouping beamforming design algorithm utilizing the near-field codebook to generate the analog beamformer. Specifically, we uniformly partition the entire large array into multiple small subarrays and design the beamforming of each subarray for the specific selected subcarrier in the whole bandwidth. The analog beamformer and digital beamformer are iteratively designed until a convergence solution is obtained. Simulation results illustrate the effectiveness of the proposed approach to mitigate near-field beam squint effect.