一种偏移载波调幅信号的频域优选新方法

A New Optimum Seeking Method for Offset Carrier Amplitude Modulated Signals in Frequency Domain

为了解决民航地空通信中机载电台接收到的多个偏移载波调幅信号互相干扰的问题,提出了一种在频域进行最佳载波搜索的优选方法。该方法采用能量重心法对接收信号的频谱幅度和频率进行校正,通过搜索频谱幅度的最大值,优选出一路载噪比最高的调幅信号进行解调,同时对其他调幅信号进行抑制。仿真实验和电台通信实验均表明该方法可以正确地实现多个偏移载波调幅信号的优选和解调,明显降低干扰,解调后话音的平均意见分提高了3分,具有实际工程应用价值。

In civil aviation offset carrier communication system,multiple offset carrier amplitude modulated (AM) signals received by airborne radio interfere with each other. To address the issue,an optimum fre-quency-domain seeking method is proposed. With the proposed method,the spectrum of received signals is corrected by using energy centrobaric method,and the AM component with maximum carrier-to-noise ratio is selected by searching the maximum amplitude of the spectrum,whereas the other offset carrier AM sig-nals are suppressed. Both computer simulation and radio communication test show that multiple offset carri-er AM signals can be selected and demodulated accurately. Meanwhile,the interference is reduced and the mean opinion score(MOS) of demodulated voice is increased by 3. This method is valuable in practical en-gineering application.