电离层色散对DS/FH-BPSK信号解调性能影响

相位连续的DS/FH(Direct Sequence/Frequency Hopping,直接序列/跳频)扩频信号的扩频带宽比直扩信号更宽,在电离层的非线性相位以及跳频频点变化这两者的共同作用下,该信号的BPSK(Binary Phase Shift Keying,二相相移键控)解调性能明显恶化。依据随机变量概率分布的数学规律,推导得到了在背景电离层色散条件和跳频频点均匀分布前提下,某种DS/FH卫星测控信号的引导信号和长周期信号BPSK误码率的变化规律,并在特定信号参数条件下进行了误码率仿真。

Impact of Ionospheric Dispersion on Demodulation of DS/FH-BPSK Signal

A phase-coherent Direct Sequence and Frequency Hopping (DS/FH) spread-spectrum signal has a much wider bandwidth than simple DS spread spectrum signals.Due to the non-linearity of ionosphere and frequency hopping scheme of the signal,Binary Phase Shift Keying (BPSK) Bit Error Rate (BER) deteriorates.Under the assumption of pure background ionospheric dispersion and a uniformly-distributed FH pattern,the BER of both the pilot signal and the long term signal in a specific DS/FH satellite link are acquired through using mathematical tools concerning the probability density functions of Random Variables (RVs).Simulations under constant ionospheric dispersion and uniformly-distributed FH pattern scintillation conditions are carried out to verify BER results.