A Reverberation Suppression Method Based on the Joint Design of a PTFM Waveform and Receiver Filter

Abstract

Transmitting waveform design and signal processing method optimization are effective ways to improve a sonar system’s detection performance. In this study, the spectrum and ambiguity function characteristics of pulse trains of frequency modulation (PTFM) signals were deduced and analyzed to address the problem of serious reverberation interference in the detection of low-speed targets in shallow water environments. The action mechanisms of PTFM signal parameters on the comb spectrum and bed of nails ambiguity function were identified. PTFM signal parameters were designed according to reverberation suppression requirements. The threshold was calculated using the estimate-before-detect method, and the comb spectrum waveform cognitive filtering detection algorithm is proposed. The simulation and lake experimental results show that the PTFM signals’ reverberation suppression ability for low-speed targets was better than it was for stationary or high-speed targets. The proposed method has good universality, which can improve the output signal-to-reverberation ratio (SRR) by more than 6 dB.

Underwater Reverberation Suppression via Attention and Cepstrum Analysis-Guided Network

“…GC has good ranging accuracy, but its high peak-to-average power leads to low emission efficiency. Li et al [8] proposed a comb spectrum waveform cognitive filtering detection algorithm, which improved the output SRR by more than 6 dB.…”

High-Resolution Wideband Waveform Design for Sonar Based on Multi-Parameter Modulation

“…It is an effective tool for signal analysis studies and waveform design, which is determined only by the transmit waveform, reflecting the point target response, parameter estimation performance, target discrimination ability, and clutter suppression ability of the system operating in the optimal receive mode [20]. However, when theoretically analyzing the performance of the designed waveform, most of the literature still directly uses the narrowband ambiguity definition for the approximate theoretical derivation of the wideband waveform [21][22][23][24], and does not use the wideband ambiguity function definition for derivation and analysis. An essential way to improve system performance is to analyze and design the wideband waveform that possesses an optimal time-frequency resolution and reverberation suppression capabilities based on the wideband ambiguity function and corresponding signal processing techniques.…”