短波多音并行信号全数字解调算法设计

Design on All-digital Demodulation Algorithm for HF Multitone Parallel Signal

针对短波多音并行信号解调算法的通用性和性能的不足,根据短波多音并行信号传输的特点,以16单音信号为例,设计了一种全数字解调算法。算法对采样速率无特殊要求,保证无失真采样即可。算法主要包括信号检测、多普勒频移测量、同步提取和FFT相位解调几部分。仿真结果表明,在S/N>12 d B的情况下,算法的丢帧率和误码率满足实用要求。算法实现简单,适合在商用PC机用VC编程和全数字接收机中实现。

In view of the universality and the performance of demodulation algorithm for HF multitone parallel signal,this paper designs an all-digital demodulation algorithm taking 16 tones as an example based on the characteristics of HF multitone parallel signal.The algorithm has no special requirements except for A / D conversion with no distortion. The algorithm consists of the following parts：signal detection,Doppler shift measurement,synchronous extraction and FFT phase demodulation. The simulation results show that the algorithm can meet the requirement of frame loss rate and bit error rate when S / N is greater than 12 d B.As the algorithm implementation is simple,the algorithm can be applied in commercial PC with VC language and all-digital receiver in real time.