Semidefinite Relaxation Based Blind Equalization using Constant Modulus Criterion

TL;DR

This paper introduces a novel blind equalization method using semidefinite relaxation and the constant modulus criterion, leveraging LDPC code asymmetry to resolve phase ambiguity.

Contribution

It proposes a new formulation combining CM criterion with relaxed code constraints and semidefinite relaxation to address phase ambiguity in blind equalization.

Findings

Effective phase ambiguity resolution demonstrated

Enhanced equalization performance with LDPC codes

Novel formulation improves blind equalization accuracy

Abstract

Blind equalization is a classic yet open problem. Statistic-based algorithms, such as constant modulus (CM), were widely investigated. One inherent issue with blind algorithms is the phase ambiguity of equalized signals. In this letter, we propose a novel scheme based on CM criterion and take advantage of the asymmetric property in a class of LDPC codes to resolve the phase ambiguity. Specifically, a new formulation with modified CM objective function and relaxed code constraints is presented.