Single branch search based pilot allocation for multi‐cell massive multiple‐input multiple‐output systems

Abstract

The performance of multi-cell massive multiple-input multiple-output systems is constrained by inter-cell interference. In this study, a pilot allocation approach is proposed to mitigate interference in such systems. The asymptotic spectral efficiency in the limit of the number of antennas is derived first. By analysing the derivatives of the spectral efficiency with the pilot allocation, a single branch search algorithm for pilot allocation is formed. In contrast, the existing approaches allocate pilots for each cell separately or with brute-force search. The analysis and numerical results show that the proposed approach is of better compromise in mitigating the interference and reducing the computational complexity.