Grouping Based Blind Interference Alignment for $K$-user MISO Interference Channels

TL;DR

This paper introduces a grouping-based blind interference alignment scheme for $K$-user MISO interference channels that adapts to short coherence times, improving degrees of freedom without relying on ideal channel assumptions.

Contribution

It proposes a novel grouping-based supersymbol structure that adjusts to channel coherence times, enhancing BIA performance in realistic scenarios.

Findings

Supersymbol length can be significantly reduced through grouping.

The proposed method achieves higher degrees of freedom than conventional approaches.

The scheme works effectively without assuming constant channels during symbol extension.

Abstract

We propose a blind interference alignment (BIA) through staggered antenna switching scheme with no ideal channel assumption. Contrary to the ideal assumption that channels remain constant during BIA symbol extension period, when the coherence time of the channel is relatively short, channel coefficients may change during a given symbol extension period. To perform BIA perfectly with realistic channel assumption, we propose a grouping based supersymbol structure for $K$-user interference channels which can adjust a supersymbol length to given coherence time. It is proved that the supersymbol length could be reduced significantly by an appropriate grouping. Furthermore, it is also shown that the grouping based supersymbol achieves higher degrees of freedom than the conventional method with given coherence time.