Beam Structured Turbo Receiver for HF Skywave Massive MIMO

TL;DR

This paper introduces a beam structured turbo receiver for HF skywave massive MIMO systems, utilizing a modified beam-based channel model and innovative signal detection methods to enhance performance and reduce complexity.

Contribution

It proposes a novel beam structured turbo receiver with a modified channel model, asymptotic optimality, and an efficient implementation for HF skywave massive MIMO communications.

Findings

Superior performance demonstrated in simulations

Low complexity of the proposed receiver

Effective interference suppression achieved

Abstract

In this paper, we investigate receiver design for high frequency (HF) skywave massive multiple-input multiple-output (MIMO) communications. We first establish a modified beam based channel model (BBCM) by performing uniform sampling for directional cosine with deterministic sampling interval, where the beam matrix is constructed using a phase-shifted discrete Fourier transform (DFT) matrix. Based on the modified BBCM, we propose a beam structured turbo receiver (BSTR) involving low-dimensional beam domain signal detection for grouped user terminals (UTs), which is proved to be asymptotically optimal in terms of minimizing mean-squared error (MSE). Moreover, we extend it to windowed BSTR by introducing a windowing approach for interference suppression and complexity reduction, and propose a well-designed energy-focusing window. We also present an efficient implementation of the windowed BSTR by exploiting the structure properties of the beam matrix and the beam domain channel sparsity. Simulation results validate the superior performance of the proposed receivers but with remarkably low complexity.