Robust Vector Perturbation Precoding Design for MIMO Broadcast Channel

TL;DR

This paper introduces a robust vector perturbation precoder for MU-MISO broadcast channels that maintains high performance despite inaccuracies in power scaling factor knowledge, addressing a key sensitivity issue in traditional VP designs.

Contribution

The paper proposes a novel MMSE-based robust VP precoder that reduces sensitivity to power scaling errors, improving performance in practical scenarios.

Findings

Robust VP precoder outperforms conventional designs in simulations.

Performance degradation due to power scaling errors is significantly mitigated.

The proposed method achieves lower error floors at high SNR.

Abstract

We consider the vector perturbation (VP) precoder design for multiuser multiple-input single output (MU-MISO) broadcast channel systems which is robust to power scaling factor errors. VP precoding has so far been developed and analyzed under the assumption that receivers could have known the power scaling factor in advance of tranmission perfectly, which is hard to obtain due to the large dynamic range and limited feedforward. However, as demonstrated in our results the performance of VP precoding is quite sensitive to the accuracy of power scaling factor and always encounter an error floor at mid to high signal-to-noise ratio (SNR) regimes. Motivated by such observations, we propose a robust VP precoder based on the minimum mean square error (MMSE) criterion. Simulation results show that, the robust VP precoder outperforms conventional VP precoding designs, as less sensitive to power scaling factor errors.