Experimental Evaluation of a Reconfigurable Antenna System for Blind Interference Alignment

TL;DR

This paper experimentally evaluates a reconfigurable antenna system for blind interference alignment in a 2-user MISO broadcast channel, demonstrating practical achievable rates and performance metrics without channel state information at the transmitter.

Contribution

It introduces a novel experimental implementation of blind IA using reconfigurable antennas on software defined radios, comparing it with traditional TDMA.

Findings

Blind IA achieves practical achievable rates with measured channels.

Reconfigurable antennas enable blind IA without CSIT.

Performance metrics like BER and error vector magnitude are favorable.

Abstract

In recent years, several experimental studies have come out to validate the theoretical findings of interference alignment (IA), but only a handful of studies have focused on blind interference alignment. Unlike IA and other interference mitigation techniques, blind IA does not require channel state information at the transmitter (CSIT). The key insight is that the transmitter uses the knowledge of channel coherence intervals and receivers utilize reconfigurable antennas to create channel fluctuations exploited by the transmitter. In this work, we present a novel experimental evaluation of a reconfigurable antenna system for achieving blind IA. We present a blind IA technique based on reconfigurable antennas for a 2-user multipleinput single-output (MISO) broadcast channel implemented on a software defined radio platform where each of the receivers is equipped with a reconfigurable antenna. We further compare this blind IA implementation with traditional TDMA scheme for benchmarking purposes. We show that the achievable rates for blind IA can be realized in practice using measured channels under practical channel conditions. Additionally, the average error vector magnitude and bit error rate (BER) performances are evaluated.