Feedback Design with VQ-VAE for Robust Precoding in Multi-User FDD Systems

TL;DR

This paper introduces a VQ-VAE-based feedback scheme for multi-user FDD systems that enhances precoding robustness and reduces pilot overhead, outperforming existing autoencoder and DFT-based methods in real-world scenarios.

Contribution

The paper presents a novel VQ-VAE feedback scheme tailored for FDD systems, improving robustness and efficiency over prior autoencoder and codebook-based approaches.

Findings

Outperforms state-of-the-art AE-based compression schemes

Reduces feedback bits or pilots needed for system deployment

Demonstrates effectiveness with real-world measurement data

Abstract

In this letter, we propose a vector quantized-variational autoencoder (VQ-VAE)-based feedback scheme for robust precoder design in multi-user frequency division duplex (FDD) systems. We demonstrate how the VQ-VAE can be tailored to specific propagation environments, focusing on systems with low pilot overhead, which is crucial in massive multiple-input multiple-output (MIMO). Extensive simulations with real-world measurement data show that our proposed feedback scheme outperforms state-of-the-art autoencoder (AE)-based compression schemes and conventional Discrete Fourier transform (DFT) codebook-based schemes. These improvements enable the deployment of systems with fewer feedback bits or pilots.