模式5是西方体制Mark XIIA敌我识别(IFF)系统的一种新模式,具有识别概率高、抗干扰能力强等特点。文中介绍了模式5使用的Walsh 扩频和预编码最小频移键控(MSK)调制技术,通过分析其调制后信号的频谱特性和时域相关特性得出模式5扩频调制技术的优势。针对模式5 信号接收处理,提出了最佳相干和非相干解调解扩算法,并结合其信号特 性分析得出,非相干解调解扩算法更适用于模式5突发通信系统。通过对两种算法进行仿真,结果表明非相干算法性能仅比最佳相干算法差1dB左右,因此工程实现中可采用该非相干解调解扩算法。

Mode 5 is a new mode of western identification friend or foe (IFF) system, it has the characteristics of high detection probability and great anti-interception performance. Firstly, in this paper the Walsh spread spectrum and precoding minimum shift keying (MSK) modulation technology used in Mode 5 are introduced, advantages of system are elaborated by analyzing the modulated signal spectrum and time domain correlation characteristics. Then, the optimal coherent and noncoherent despreading algorithms are proposed for Mode 5 signal reception processing, and the noncoherent despreading algorithm is more suitable since Mode 5 system is a burst communication system. Both of the algorithms are simulated, the simulation results show that there is only 1 dB performance difference between the two algorithms. Therefore, the noncoherent despreading algorithm can be used in engineering implementation.

TN958. 96