# Base Station Selection for Massive MIMO Networks with Two-stage Precoding

## TL;DR

This paper proposes a base station selection scheme to mitigate angle-spreading-range overlap in massive MIMO systems with two-stage precoding, improving performance by maximizing SINR and SLNR.

## Contribution

It introduces a novel BS selection method using SLNR maximization and a low-overhead algorithm with a lower bound on average SLNR for massive MIMO systems.

## Key findings

- The proposed schemes effectively mitigate ASR overlap.
- Numerical simulations demonstrate improved system performance.
- The algorithms achieve low complexity and overhead.

## Abstract

The two-stage precoding has been proposed to reduce the overhead of both the channel training and the channel state information (CSI) feedback for the massive multiple-input multiple-output (MIMO) system. But the overlap of the angle-spreading-ranges (ASR) for different user clusters may seriously degrade the performance of the two-stage precoding. In this letter, we propose one ASR overlap mitigating scheme through the base station (BS) selection. Firstly, the BS selection is formulated as a sum signal-to-interference-plus-noise ratio (SINR) maximization problem. Then, the problem is solved by a low-complex algorithm through maximizing signal-to-leakage-plus-noise ratio (SLNR). In addition, we propose one low-overhead algorithm with the lower bound on the average SLNR as the objective function. Finally, we demonstrate the efficacy of the proposed schemes through the numerical simulations.