Optimal Waveform Design Using Frequency-Modulated Pulse Trains for Active Sonar

Abstract

Frequency-modulated pulse trains can be applied in active sonar systems to improve the performance of conventional transmitted waveforms. Recently, two pulse trains have been widely researched as the transmitted waveforms for active sonars. The LFM-Costas pulse train was formed by modulating the linear frequency-modulated (LFM) waveform via the Costas sequence to remove the Doppler ambiguity of LFM pulses. The generalized sinusoidal frequency-modulated (GSFM) waveform, another frequency-modulated pulse train, achieved an ideal ambiguity function shape with thumbtack mainlobe. In this paper, we focus on constructing an optimization model to optimize the LFM-Costas and GSFM pulse trains with the genetic algorithm. The pulse trains can be improved on properties of both ambiguity function and correlations between sub-pulses. The optimized pulse trains are proven to have better detection performance than those of the initial pulse trains, including the lower sidelobe levels of ambiguity function, as well as lower cross-correlation property. Moreover, it is affirmed that the reverberation suppression performance of pulse trains has also been improved through the optimization model.

Costas‐code‐based radar waveform design using adaptive weights with target scattering coefficients and optimal variable time spacing with improved ambiguity function

“…The column 1 of Table 2 represents the average ACF SLLs of adaptive WVTSC waveform. The ‘average sidelobe’ metric was recently used in [14]. The column 2 shows the resultant PSL of the waveform ACF.…”

“…Therefore, we will adjust the models proposed in [12, 13] by incorporating them into a single model. The authors in [14] proposed an optimised waveform for sonar application. Our VTS optimisation approach is quasi similar, but for the radar case.…”

LRS: A Positive and Negative Linear Frequency Modulation Method for Ranging and Speed Measurement

“…Grimmett et al [13] proposed a method that involved using an echo-ranging system to transmit a continuously repeating linear frequency modulated signal through a propagation medium and receive a return signal reflected off of a target, performing signal processing on the return signal, extracting detected echo sets from the processing intervals, estimating a target range-rate using the estimated time versus delay slopes, computing a bias error using the estimated target range-rate, applying timing correction to the detected echo sets to remove the bias error. Guan, Chengyu et al [14] focused on constructing an optimization model to optimize the LFM-Costas and GSFM pulse trains with the genetic algorithm. The pulse trains can be improved on properties of both ambiguity function and correlations between sub-pulses.…”

Design of Optimized Coded LFM Waveform for Spectrum Shared Radar System

“…Instead of designing orthogonal waveforms, several studies have focused on improving orthogonal waveforms by using a pulse train or modifying a matched filter. In [15], the authors mentioned the range-Doppler ambiguity problem of several optimal waveforms and proposed a method to generate optimal frequency-modulated pulse trains to alleviate this problem. In [16], an orthogonal waveform called DFCCW was implemented.…”