The Study Of Phase Locking Reception Feature For The CW Pulse Signal

In the underwater acoustic signal processing field, due to the relative motion between the sonar and the target will cause the signal frequency shift. Under the large depth or distance location conditions, noise ratio of the signal that the transducer receives becomes low. Under these circumstances narrowband filter will improve the SNR. For large changes of the center frequency, the bandwidth of signal is relatively little variation; the conventional analog filter hardware is difficult to achieve a narrow-band filter.Phase-locked loop has a unique narrowband tracking filter performance, can achieve good phase-locked tracking filter of continuous signal. Due to the CW pulse signal of popular sonar signal is narrow pulse signal, phase locked loop will enter a losing lock each cycle, it is difficult to achieve phase-locked tracking filter.Thesis researches on phase-locked reception feature of CW pulse signal. Firstly, conduct a comparative study of the phase-locked loop simulation and circuit measuring of PLL CD4046 chip. Study the phase-locked loop through software simulation under different parameters on the signal capture transient response, including changes in CW pulse signal parameters and phase-locked loop circuit parameters. Secondly,by measuring a hardware circuit of the phase-locked loop, obtain the CW pulse signal capture feature of the phase-locked loop. By comparison of the measurements, thesis gets the conclusion of the CW pulse signal reception characteristics of the phase-locked loop. Finally, according to the phase-locked loop on the CW pulse signal capture feature, design a PLL-based CW pulse circuits Sonar receiver. Using the PLL CD4046 chip study and design a phase-locked loop sonar receiver which achieve a narrow-band filter function, then compare with the conventional sonar receiver.The results of circuit debugging show that: the phase-locked loop sonar receiver can achieve a narrow-band filter function and capture signal successfully. And the phase-locked loop sonar receiver is able to meet the accuracy requirements of the sonar receiver.