$\ell^p\!-\!\ell^q$-Norm Minimization for Joint Precoding and Peak-to-Average-Power Ratio Reduction

TL;DR

This paper introduces a novel $ ext{l}^p ext{-} ext{l}^q$-norm based method for joint precoding and peak-to-average power ratio reduction in massive MU-MIMO-OFDM systems, achieving significant PAR reduction without increasing EVM or OOB emissions.

Contribution

It proposes a new $ ext{l}^p ext{-} ext{l}^q$-norm formulation for joint precoding and PAR reduction, with theoretical analysis and low-complexity simulation results.

Findings

Significant PAR reduction demonstrated in simulations.

No increase in EVM or OOB emissions observed.

Method suitable for massive MU-MIMO-OFDM systems.

Abstract

Wireless communication systems that rely on orthogonal frequency-division multiplexing (OFDM) suffer from a high peak-to-average (power) ratio (PAR), which necessitates power-inefficient radio-frequency (RF) chains to avoid an increase in error-vector magnitude (EVM) and out-of-band (OOB) emissions. The situation is further aggravated in massive multiuser (MU) multiple-input multiple-output (MIMO) systems that would require hundreds of linear RF chains. In this paper, we present a novel approach to joint precoding and PAR reduction that builds upon a novel $\ell^p\!-\!\ell^q$-norm formulation, which is able to find minimum PAR solutions while suppressing MU interference. We provide a theoretical underpinning of our approach and provide simulation results for a massive MU-MIMO-OFDM system that demonstrate significant reductions in PAR at low complexity, without causing an increase in EVM or OOB emissions.