图样调制跳频系统的帧同步算法与性能分析

Synchronization method for pattern modulation frequency hopping system and on its performance analyses

为提高跳频通信的抗干扰性能,设计一种新的短波跳频通信技术——图样调制跳频(pattern modulation frequency hopping,PMFH)系统。该系统将跳点分组,以载波发射的相对位置代表信息比特。通过增加调制域的冗余度和基带信号能量,以频带和功率资源换取信噪比,同时保护了跳频序列。为克服跳同步后静默时间对信号帧同步的影响,设计同步字检测方案和多图样匹配方案。结果证明:多图样匹配方案的性能较好,在信噪比大于0dB时,7位Gold图样的帧同步概率不小于80%,31位Gold图样的帧同步概率不小于95%,图样调制跳频技术使跳频通信在恶劣信道中的可靠性显著提高。

In order to improve the anti-jamming performance of frequency hopping communication, this paper presented a new FH system, namely pattern modulation frequency hopping （PMFH） system. The system groups the hopping frequencies, and the presence of FH carriers in the group represented the information. By increasing the redundancy of modulation domain and the energy of baseband signal, the SNR and hide the FH pattern were improved. Considering the silence time during the communication, synchronization word detection scheme and multi-sequence matching scheme were put forward for frame synchronization. It is proved that the multi-pattern matching scheme perform better. When SNR is greater than 0 dB, the frame synchronization probability of the system using Gold pattern with length of 7 reaches is not less than 80% and that for length of 31 is not less than 95%. The reliability of FH communication in severe channel is improved Significantly by using pattern matching frequency hopping technique.