Demo: Non-classic Interference Alignment for Downlink Cellular Networks

TL;DR

This paper demonstrates a practical implementation of non-classic interference alignment in downlink cellular networks, showing capacity gains by reducing inter-cell interference without complex coordination.

Contribution

It provides a hardware-based demonstration of a recent interference management scheme that reduces inter-cell interference through channel estimation and feedback, without requiring complex coordination.

Findings

Achieved measurable capacity gains in a controlled hardware environment.

Validated the effectiveness of the interference alignment scheme across different channel conditions.

Showed feasibility of implementing non-classic interference alignment in real hardware.

Abstract

Our demo aims at proving the concept of a recent proposed interference management scheme that reduces the inter-cell interference in downlink without complex coordination, known as non-classic interference alignment (IA) scheme. We assume a case where one main Base Station (BS) needs to serve three users equipments (UE) while another BS is causing interference. The primary goal is to construct the alignment scheme ; i.e. each UE estimates the main and interfered channel coefficients, calculates the optimal interference free directions dropped by the interfering BS and feeds them back to the main BS which in turn applies a scheduling to select the best free inter-cell interference directions. Once the scheme is build, we are able to measure the total capacity of the downlink interference channel. We run the scheme in CorteXlab ; a controlled hardware facility located in Lyon, France with remotely programmable radios and multi-node processing capabilities, and we illustrate the achievable capacity gain for different channel realizations.