Improved OMP Approach to Sparse Multi-path Channel Estimation via Adaptive Inter-atom Interference Mitigation

TL;DR

This paper introduces an adaptive inter-atom interference mitigation method for orthogonal matching pursuit, significantly enhancing sparse multi-path channel estimation accuracy, especially in challenging scenarios with large delay spreads and limited training data.

Contribution

It proposes a novel adaptive IAI mitigation technique that improves OMP performance by designing an adaptive sensing dictionary and utilizing posterior information.

Findings

The proposed method outperforms ordinary OMP in simulation tests.

Adaptive IAI mitigation reduces false atom selection.

Enhanced channel estimation accuracy in complex scenarios.

Abstract

Since most components of sparse multi-path channel (SMPC) are zero, impulse response of SMPC can be recovered from a short training sequence. Though the ordinary orthogonal matching pursuit (OMP) algorithm provides a very fast implementation of SMPC estimation, it suffers from inter-atom interference (IAI), especially in the case of SMPC with a large delay spread and short training sequence. In this paper, an adaptive IAI mitigation method is proposed to improve the performance of SMPC estimation based on a general OMP algorithm. Unlike the ordinary OMP algorithm, a sensing dictionary is designed adaptively and posterior information is utilized efficiently to prevent false atoms from being selected due to serious IAI. Numeral experiments illustrate that the proposed general OMP algorithm based on adaptive IAI mitigation outperform both the ordinary OMP algorithm and the general OMP algorithm based on non-adaptive IAI mitigation.