Pilot Assignment in Cell-Free Massive MIMO: A Low-Complexity Clusterization Technique

In this paper, we present a novel pilot assignment algorithm leveraging a low-complexity clustering approach for cell-free massive MIMO networks. The proposed algorithm utilizes the geographical positions of users to refine user clustering and pilot allocation. A low-complexity iterative migration of users across neighbouring clusters is employed to enhance the average data rate and achieve an optimal user count per cluster, in alignment with the finite orthogonal pilot signals used. Comparative simulation results show the superior performance of our proposed method in data rate enhancement while maintaining a reduced complexity relative to existing pilot assignment techniques in the literature.