Feasibility Conditions of Interference Alignment via Two Orthogonal Subcarriers

TL;DR

This paper establishes conditions on subcarrier spacing in OFDM systems to enable interference alignment, maximizing degrees-of-freedom and approaching the upper bound on sum-rate.

Contribution

It derives specific feasibility conditions for interference alignment in line-of-sight channels using only subcarrier spacing, a novel approach in OFDM systems.

Findings

Maximal degrees-of-freedom are achieved.

Upper bound on sum-rate can be approached arbitrarily closely.

Feasibility conditions depend solely on subcarrier spacing.

Abstract

Conditions are derived on line-of-sight channels to ensure the feasibility of interference alignment. The conditions involve choosing only the spacing between two subcarriers of an orthogonal frequency division multiplexing (OFDM) scheme. The maximal degrees-of-freedom are achieved and even an upper bound on the sum-rate of interference alignment is approached arbitrarily closely.