A variable step-size gradient adaptive lattice algorithm for multiple sinusoidal interference cancelation

Seong-Woo Kim,Young-Cheol Park,Dae Hee Youn

doi:10.1186/1687-6180-2013-106

Seong-Woo Kim, Young-Cheol Park + Show 1 more

Open Access

https://doi.org/10.1186/1687-6180-2013-106

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Abstract

Abstract In passive sonar, adaptive algorithms can be used to cancel strong sinusoidal self-interferences. In order to correctly recover low-power target signals during the early stages of processing, these adaptive algorithms must provide fast convergence and, at the same time, narrow notches at the frequencies of the sinusoids. In this respect, the gradient adaptive lattice (GAL) algorithm is a very attractive choice. However, the GAL algorithm with a constant step-size parameter has to compromise between the convergence rate and notch bandwidths. Therefore, in this article, we propose a variable step-size scheme for the GAL algorithm that can achieve both a fast convergence rate and narrow notches. Simulation results demonstrate the efficiency of the proposed algorithm compared to both the conventional GAL algorithm and transversal adaptive filter combined with the variable step-size scheme.

Highlights

The performance of passive sonar is degraded by strong self-interference originating from the machinery of its own ship [1]
An adaptive noise cancelation (ANC) algorithm should be able to form narrow notches in order to filter out self-interference without distorting the low-power target signal in a passive sonar signal [3]
The least mean square (LMS)-type transversal adaptive filters produce notch bandwidths proportional to interference amplitudes [3,5], which can result in the distortion of the target signal in passive sonar especially when the interference has strong amplitude

Summary

Introduction

The performance of passive sonar is degraded by strong self-interference originating from the machinery of its own ship [1]. It has been proven that the VSS-GAL algorithm in steady-state recovers the target signal power at the final stage of the lattice filter. −31.39 −35.72 −40.58 the proposed VSS-GAL algorithm is able to recover the target signal with much lower distortion than the other algorithms This is because the proposed VSS-GAL algorithm produces accurate notches with narrow bandwidths which are independent of the amplitudes of sinusoidal interferences and proportionate only to the step-size parameter. EMSE results indicate that the proposed VSS-GAL algorithm recovers the target signal power with much less distortions than both the VSS-NLMS algorithm and the VSS-GAL algorithm in [15]

Conclusions

Findings

Filter order