Interference Alignment via Improved Subspace Conditioning

TL;DR

This paper introduces a low complexity interference alignment method for frequency selective SISO channels that enhances sum rate performance by combining IA with MMSE decoding without sacrificing degrees of freedom.

Contribution

It presents a novel IA precoding design that improves sum rate in frequency selective channels by integrating MMSE decoding, maintaining the original degrees of freedom.

Findings

Enhanced sum rate performance in simulations

Preservation of degrees of freedom at K/2

Low complexity implementation

Abstract

For the K user, single input single output (SISO), frequency selective interference channel, a new low complexity transmit beamforming design that improves the achievable sum rate is presented. Jointly employing the interference alignment (IA) scheme presented by Cadambe and Jafar in [1] and linear minimum mean square error (MMSE) decoding at the transmitters and receivers, respectively, the new IA precoding design improves the average sum rate while preserving the achievable degrees of freedom of the Cadambe and Jafar scheme, K/2.