A Phase-Coded Sequence Design Method for Active Sonar.

Chengyu Guan,Zemin Zhou,Xinwu Zeng

doi:10.3390/s20174659

Chengyu Guan, Zemin Zhou + Show 1 more

Open Access

https://doi.org/10.3390/s20174659

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Abstract

Phase-coded sequences are widely studied as the transmitted signals of active sonars. Recently, several design methods have been developed to generate phased-coded sequences satisfying specific aperiodic or periodic autocorrelation sidelobe level metrics. In this paper, based on the majorization–minimization strategy and the squared iterative acceleration scheme, we propose a method to generate sequences with the periodic weighted integrated sidelobe level metric. Numerical simulations illustrate that the proposed method can effectively suppress the periodic autocorrelation sidelobe levels in specific time lags. Compared with other sequence design methods satisfying the periodic weighted integrated sidelobe level metric, our method improves the computational efficiency significantly. In addition, the proposed sequence demonstrates better matched filter performance in specific range intervals compared with its counterpart. The results suggest that the method could be applied as a valid and real-time design method for transmitted signals of active sonars.

Highlights

The autocorrelations of transmitted signals are of great significance for the signal processing in active sonars
A good autocorrelation property indicates that the signal is nearly uncorrelated with its own time-delay versions [1,2], which ensures that the active sonar can precisely extract the echo information from the interested time lags while suppressing interferences from other time lags [3,4]
We prove the validity of the proposed method and compare its convergence with two relevant methods, including the PeCA method which generates sequences with periodic Weighted Integrated Sidelobe Level (WISL) metric [19]

Summary

Introduction

The autocorrelations of transmitted signals are of great significance for the signal processing in active sonars. For a phase-coded sequence satisfying the ISL metric, it is difficult and time-consuming to suppress autocorrelation sidelobes at all time lags. The WISL metric is developed to reduce autocorrelation sidelobe levels at specific time lags [13]. Hao He proposed the periodic CA (PeCA) to generate sequence sets with the periodic WISL metric based on the SVD operations [19]. We intended to apply the MM strategy for the periodic WISL Equation and proposed a real-time sequence design method.

MM Based Phase-Coded Sequence Design Method

Simulations and Results

Matched

Conclusions