Used For Audio And Video Signal Processing Research And Implementation Method Of Modulation Signal

The modulation signals and the driving signals used for acousto-optic correlator which is based on acousto-optic signal processing technique were researched and created through the radar signal theory in this paper. The modulation signal generator of acousto-optic correlator was optimized and the nature of the signals became more diverse. The method of creating the modulation signal used for acousto-optic correlator was researched and the modulation signal and driving signal generator based on FPGA and MCU was designed and made in this paper. Finally, the modulation signals and the driving signals were realized.The hardware circuit and software of the signal generator was designedaccording to the requirement for the modulation signal and the driving signal of the acousto-optic correlator. Some digital signal processing modules were designed by programming in FPGA using Verilog HDL. The communication between FPGA and MCU was realized and the communication between FPGA and computer through USB was realized also. Some other functions were also realized, such as inputing the frequency of the modulation signa、some display functions and application program.Finally, the driving signal and the modulation signal using for the acousto-optic correlator were created through transforming the digital signal to analog signal through DAC.Some common signals under different frequencies were simulated using the signal generator made in this paper, such as the sine wave、square wave and sawtooth wave and the results were compared and analyzed. According to the requirement for the modulation signal of the acousto-optic correlator and radar signal theory, some radar signals were simulated, such as the linear FM pulse compression signal and phase coded pulse compression signal. The linear FM pulse compression signal was simulated under different sampling rates、start frequencies and frequency ranges. Phase coded pulse compression signals were simulated in the case that5bit、11bit and13bit barker codes were used as modulation signals. Finally, the results were compared and analyzed.