Optimizing RRH Placement Under a Noise-Limited Point-to-Point Wireless Backhaul

TL;DR

This paper analyzes RRH placement in distributed networks with wireless backhaul, showing that large backhaul bandwidth and distributed antennas improve spectral efficiency despite noise limitations.

Contribution

It introduces an optimization framework for RRH deployment considering zero-forcing beamforming and backhaul constraints, highlighting the benefits of distributed antennas.

Findings

Large backhaul bandwidth is necessary for optimal RRH deployment.

Distributed antennas outperform co-located systems in spectral efficiency.

Wireless backhaul scheme impacts deployment strategies and network performance.

Abstract

In this paper, we study the deployment decisions and location optimization for the remote radio heads (RRHs) in coordinated distributed networks in the presence of a wireless backhaul. We implement a scheme where the RRHs use zero-forcing beamforming (ZF-BF) for the access channel to jointly serve multiple users, while on the backhaul the RRHs are connected to their central units (CUs) through point-to-point wireless links. We investigate the effect of this scheme on the deployment of the RRHs and on the resulting achievable spectral efficiency over the access channel (under a backhaul outage constraint). Our results show that even for noise-limited backhaul links, a large bandwidth must be allocated to the backhaul to allow freely distributing the RRHs in the network. Additionally, our results show that distributing the available antennas on more RRHs is favored as compared to a more co-located antenna system. This motivates further works to study the efficiency of wireless backhaul schemes and their effect on the performance of coordinated distributed networks with joint transmission.