Positioning and transmission in cell-free networks: ambiguity function, and MRC/MRT array gains

TL;DR

This paper explores the dual use of cell-free networks for positioning and data transmission, analyzing ambiguity functions and array gains with non-zero bandwidth waveforms through theoretical and computational methods.

Contribution

It provides a combined analysis of positioning metrics and communication array gains in cell-free networks, considering waveform bandwidth effects.

Findings

Ambiguity function analysis reveals resolution and ambiguity characteristics.

Array gain performance is characterized for MRT and MRC schemes.

Waveform bandwidth impacts both positioning accuracy and communication gains.

Abstract

Cell-free network is a new paradigm, originating from distributed MIMO, that has been investigated for a few recent years as an alternative to the celebrated cellular structure. Future networks not only consider classical data transmission but also positioning, along the lines of Integrated Communications and Sensing (ISAC). The goal of this paper is to investigate at the same time the ambiguity function which is an important metric for positioning and the understanding of its associated resolution and ambiguities, and the array gain when maximum ratio transmission (MRT) or MR combining (MRC) is implemented for data communications. In particular, the role and impact of using a waveform with non-zero bandwidth is investigated. The theoretical findings are illustrated by means of computational results.