Joint Power-control and Antenna Selection in User-Centric Cell-Free Systems with Mixed Resolution ADC

TL;DR

This paper introduces a joint optimization scheme for power control and antenna selection in user-centric cell-free systems with mixed ADC resolutions, aiming to maximize uplink sum rate under energy constraints.

Contribution

It proposes a novel joint optimization framework using BPSO and SCA for UC CF-mMIMO systems with mixed ADCs, including an approximate uplink rate expression.

Findings

Optimized power and antenna selection improve uplink sum rate.

Mixed ADC resolution impacts system performance and energy efficiency.

The proposed method outperforms baseline approaches.

Abstract

In this paper, we propose a scheme for the joint optimization of the user transmit power and the antenna selection at the access points (AP)s of a user-centric cell-free massive multiple-input-multiple-output (UC CF-mMIMO) system. We derive an approximate expression for the achievable uplink rate of the users in a UC CF-mMIMO system in the presence of a mixed analog-to-digital converter (ADC) resolution profile at the APs. Using the derived approximation, we propose to maximize the uplink sum rate of UC CF-mMIMO systems subject to energy constraints at the APs. An alternating-optimization solution is proposed using binary particle swarm optimization (BPSO) and successive convex approximation (SCA). We also study the impact of various system parameters on the performance of the system.