A methodology for efficient antenna deployment in distributed massive multiple-input multiple-output systems

Abstract

This paper, taking as reference channel data previously obtained by using a rigorous and well-tested ray-tracing method for a concentrated massive multiple-input multiple-output (mMIMO) system, focuses on the optimization of the set of potential antennas required in a distributed mMIMO system to achieve the same channel spectral efficiency as the concentrated system. Concerning the optimizer, a binary particle swarm optimization algorithm was considered to decide whether to activate or deactivate any of the antennas within the original mesh, taking into account, in order to direct the search, the total spectral efficiency, the equality between the spectral efficiency of users, and the number of receiver antennas at the distributed base station. The analysis was carried out in a large indoor environment at the 5G n258 frequency band (26 GHz), concentrating on the up-link and considering a set of 20 uniformly distributed active users. The results obtained show that, in the distributed mMIMO system, an arrangement with fewer than half the number of receiver antennas of the initial mesh is required to achieve a similar performance to that of the concentrated one taken as a reference.