Turbo-Equalization Using Partial Gaussian Approximation

TL;DR

This paper introduces a turbo-equalization algorithm that employs partial Gaussian approximation and expectation propagation, significantly improving performance and reducing complexity in ISI channel data transmission.

Contribution

It presents a novel message-passing turbo-equalizer using PGA and expectation propagation, with reduced complexity tailored for ISI channels.

Findings

Significant performance gains over existing turbo-equalizers

Reduced computational complexity through channel-specific structure exploitation

Effective trade-off between performance and complexity

Abstract

This paper deals with turbo-equalization for coded data transmission over intersymbol interference (ISI) channels. We propose a message-passing algorithm that uses the expectation-propagation rule to convert messages passed from the demodulator-decoder to the equalizer and computes messages returned by the equalizer by using a partial Gaussian approximation (PGA). Results from Monte Carlo simulations show that this approach leads to a significant performance improvement compared to state-of-the-art turbo-equalizers and allows for trading performance with complexity. We exploit the specific structure of the ISI channel model to significantly reduce the complexity of the PGA compared to that considered in the initial paper proposing the method.