Environment-Aware Beam Selection for Efficient Codebook Design in IRS-Assisted Communications

This paper proposes an environment-aware beam selection method for codebook design to reduce the overhead in intelligent reflecting surface (IRS)-assisted communication systems. Conventional communication methods face a challenge in that the time required to obtain channel state information (CSI) is enormous. Therefore, this paper focuses on data transmission using a codebook-based beam search. Because the search time depends on the number of search beams, reducing the number of beams leads to a reduction in the search time. Conversely, reducing the number of search beams leads to a reduction in the search accuracy and reduces the amount of user equipment (UEs) that can be supported by the IRS. To solve this tradeoff, we propose a beam selection method to construct a codebook by considering the surrounding environment. The effectiveness of the proposed beam selection method is evaluated using simulations. The results show that the search time is reduced with the high search accuracy by using the proposed method. This method contributes to reducing the overhead in the system and meeting the increasing communication demands.