副载波对广播信号的频谱和模糊函数的影响

根据调频立体声广播中副载波的产生原理,针对广播信号的频谱和模糊函数图进行分析,指出:有副载波的广播信号的模糊函数图的零距离切面在导频信号的二分频的整数倍上出现相关峰、多普勒切面则由无副载波的广播信号的模糊函数图的多个多普勒切面加权相加而成;同时带宽较窄的有副载波的广播信号的模糊函数图的相关峰呈现多峰.最后给出了消除多峰的方法和实录信号的处理结果.

The Effect of Sub-Carriers on the Spectra and Ambiguity Functions of FM Stereo Broadcast Signals

According to the theory of generation of the sub-carriers in FM stereo broadcast,an analysis of the spectra and ambiguity functions of FM stereo signals is made.The authors point out that there are correlation peaks in the zero distance section planes of ambiguity functions of FM stereo broadcast signals with sub-carriers with a period of one half of the frequency of the pilot signals,and the Doppler section planes of ambiguity functions of FM stereo broadcast signals with sub-carriers are weighted summation of those of ambiguity functions of FM stereo broadcast signals without sub-carriers,and there are multi-peaks(correlation peak) in the ambiguity functions of the broadcast signals with sub-carriers and narrow bandwidth.The method of cancellation of the multi-peaks and the results of processing of the recorded data are also presented.