An SINR-Optimized AP Selection Algorithm Based on Cell-Free Massive MIMO Systems

With the rapid advancement of wireless communication technologies, cell-free massive Multiple-Input Multiple-Output (MIMO) systems have emerged as a promising solution to meet the increasing demands for high data rates and extensive coverage. However, the dense deployment of Access Points (APs) in such systems introduces significant fronthaul burdens and system complexities. This paper proposes an SINR optimized AP selection algorithm that incorporates load balancing constraints to enhance the average Signal-to-Interference-plusNoise Ratio (SINR) for users while ensuring a balanced distribution of load across APs. The algorithm employs spectral clustering for user grouping based on their locations and channel gains, constructs a limited AP candidate set for each user to reduce fronthaul overhead, and selects the optimal AP for each user by maximizing the expected SINR under load constraints. Simulation results demonstrate that the proposed algorithm significantly improves user average SINR and achieves effective load balancing compared to conventional AP selection schemes.