Turbo Equalization with Coarse Quantization using the Information Bottleneck Method

TL;DR

This paper introduces a turbo equalizer for ISI channels that employs coarse quantization and the information bottleneck method to optimize mutual information, resulting in improved area efficiency and error correction performance.

Contribution

It presents a novel turbo equalizer design using LUTs optimized with the information bottleneck method for coarse quantization, enhancing efficiency and performance.

Findings

Coarse quantization LUTs can outperform traditional equalizers in area efficiency.

Turbo setups with coarse quantization improve error correction over non-turbo configurations.

Simplified LUT structures effectively incorporate decoder feedback with reduced complexity.

Abstract

This paper proposes a turbo equalizer for intersymbol interference channels (ISI) that uses coarsely quantized messages across all receiver components. Lookup tables (LUTs) carry out compression operations designed with the information bottleneck method aiming to maximize relevant mutual information. The turbo setup consists of an equalizer and a decoder that provide extrinsic information to each other over multiple turbo iterations. We develop simplified LUT structures to incorporate the decoder feedback in the equalizer with significantly reduced complexity. The proposed receiver is optimized for selected ISI channels. A conceptual hardware implementation is developed to compare the area efficiency and error correction performance. A thorough analysis reveals that LUT-based configurations with very coarse quantization can achieve higher area efficiency than conventional equalizers. Moreover, the proposed turbo setups can outperform the respective non-turbo setups regarding area efficiency and error correction capability.