Error Probability Analysis and Power Allocation for Interference Exploitation Over Rayleigh Fading Channels

TL;DR

This paper analyzes the performance of constructive interference precoding in MU-MIMO systems with PSK modulation, deriving new analytical expressions for SEP and optimizing power allocation to significantly improve error rates and throughput.

Contribution

It provides new exact and asymptotic SEP expressions, introduces power allocation schemes based on SEP minimization, and compares CI precoding performance with conventional methods.

Findings

CI precoding outperforms traditional interference suppression with up to 20dB SNR gain in SEP

Power allocation schemes based on SEP reduce required SNR by up to 13dB

Derived analytical expressions for throughput and power efficiency in MU-MIMO systems

Abstract

This paper considers the performance analysis of constructive interference (CI) precoding technique in multi-user multiple-input multiple-output (MU-MIMO) systems with a finite constellation phase-shift keying (PSK) input alphabet. Firstly, analytical expressions for the moment generating function (MGF) and the average of the received signal-to-noise-ratio (SNR) are derived. Then, based on the derived MGF expression the average symbol error probability (SEP) for the CI precoder with PSK signaling is calculated. In this regard, new exact and very accurate asymptotic approximation for the average SEP are provided. Building on the new performance analysis, different power allocation schemes are considered to enhance the achieved SEP. In the first scheme, power allocation based on minimizing the sum symbol error probabilities (Min-Sum) is studied, while in the second scheme the power allocation based on minimizing the maximum SEP (Min-Max) is investigated. Furthermore, new analytical expressions of the throughput and power efficiency of the CI precoding in MU-MIMO systems are also derived. The numerical results in this work demonstrate that, the CI precoding outperforms the conventional interference suppression precoding techniques with an up to 20dB gain in the transmit SNR in terms of SEP, and up to 15dB gain in the transmit SNR in terms of the throughput. In addition, the SEP-based power allocation schemes provide additional up to 13dB gains in the transmit SNR compared to the conventional equal power allocation scheme.