Receiver Architectures for MIMO-OFDM Based on a Combined VMP-SP Algorithm

TL;DR

This paper introduces a flexible MIMO-OFDM receiver architecture using a combined VMP-SP message-passing algorithm, enabling iterative estimation, equalization, and decoding with superior performance demonstrated through simulations.

Contribution

It develops a novel combined VMP-SP message-passing framework for MIMO-OFDM receivers, adaptable to various complexity and performance requirements.

Findings

High performance demonstrated through Monte Carlo simulations

Superiority over heuristic approaches confirmed

Flexible receiver structures tailored to application needs

Abstract

Iterative information processing, either based on heuristics or analytical frameworks, has been shown to be a very powerful tool for the design of efficient, yet feasible, wireless receiver architectures. Within this context, algorithms performing message-passing on a probabilistic graph, such as the sum-product (SP) and variational message passing (VMP) algorithms, have become increasingly popular. In this contribution, we apply a combined VMP-SP message-passing technique to the design of receivers for MIMO-ODFM systems. The message-passing equations of the combined scheme can be obtained from the equations of the stationary points of a constrained region-based free energy approximation. When applied to a MIMO-OFDM probabilistic model, we obtain a generic receiver architecture performing iterative channel weight and noise precision estimation, equalization and data decoding. We show that this generic scheme can be particularized to a variety of different receiver structures, ranging from high-performance iterative structures to low complexity receivers. This allows for a flexible design of the signal processing specially tailored for the requirements of each specific application. The numerical assessment of our solutions, based on Monte Carlo simulations, corroborates the high performance of the proposed algorithms and their superiority to heuristic approaches.