变采样率全数字相位载波解调技术

Multirate digital phase generated carrier demodulation

基于相位载波(PGC,Phase Generated Carrier)解调各环节的信号频率范围,提出变采样率解调方案,解决高采样频率下的实时全数字PGC解调问题.对干涉输出信号采用高采样率进行模数转换,提高解调带宽和动态范围.对混频相乘和低通滤波后的环节采用降低采样率处理,减少实时数字信号处理的运算量.设计变采样率全数字PGC解调系统,采用现场可编程门阵列(FPGA,Field Programmable Gate Arrays)并行实现混频相乘和低通滤波环节,采用数字信号处理器(DSP,Digital Signal Processor)实现后续解调环节,实现采样率高达1 MHz的实时解调.实验结果表明频率为5 kHz、幅度为1 rad的被测信号可以被有效解调.

Based on the signal bandwidth in each phase generated carrier （PGC） demodulation procedure, a multirate demodulation scheme was proposed to solve the real time digital PGC demodulation problem at high sampling rate. The interfered output was analog-to-digital converted at high sampling rate to improve demodulation bandwidth and dynamic range. The procedures after frequency mixing and low pass filtering were down sampled and digital PGC demodulation computation was reduced. A digital PGC demodulation system was designed and implemented. The frequency mixing and low pass filtering procedures were implemented using field programmable gate arrays （FPGA） and the following procedures were implemented using digital signal processor （DSP）. Real-time demodulation experiment verified that a test signal with 5 kHz and 1 rad was successfully demodulated at 1 MHz sampling rate.