Interference Alignment for Partially Connected MIMO Cellular Networks

TL;DR

This paper introduces an iterative interference alignment algorithm tailored for partially connected MIMO cellular networks, effectively addressing topology challenges and exploiting partial connectivity to enhance degrees of freedom.

Contribution

It proposes a novel three-stage IA algorithm specifically designed for partially connected MIMO cellular networks, improving DoF over conventional methods.

Findings

Significant DoF gain due to partial connectivity

Algorithm effectively manages overlapping links in MIMO cellular topology

Derived DoF bound compatible with fully connected channels

Abstract

In this paper, we propose an iterative interference alignment (IA) algorithm for MIMO cellular networks with partial connectivity, which is induced by heterogeneous path losses and spatial correlation. Such systems impose several key technical challenges in the IA algorithm design, namely the overlapping between the direct and interfering links due to the MIMO cellular topology as well as how to exploit the partial connectivity. We shall address these challenges and propose a three stage IA algorithm. As illustration, we analyze the achievable degree of freedom (DoF) of the proposed algorithm for a symmetric partially connected MIMO cellular network. We show that there is significant DoF gain compared with conventional IA algorithms due to partial connectivity. The derived DoF bound is also backward compatible with that achieved on fully connected K-pair MIMO interference channels.