卫星导航信号设计中调制方式的新选择

针对在拥挤的L频段设计更高性能卫星导航信号体制的问题，提出该频段部分信号采用最小频移键控(minimum shift keying, MSK)调制。首先建立最小频移键控-二进制偏移载波（minimum shift keying binary offset carrier， MSK-BOC）调制的通用数学模型，然后以典型的GPS L1-CA、GPS L1-P(Y)和GPS L1-M信号为例，仿真并对比讨论了这3种信号分别采用MSK调制和二相移相键控（binary phase shift keying, BPSK)调制时的码跟踪误差、多径误差包络、自相关函数和功率谱密度。分析结果表明，当卫星导航信号满足一定条件时，采用MSK调制能够获得比BPSK调制更好的性能，论证了在卫星导航系统L频段采用MSK调制的可能性。

New option for modulation in GNSS signal design

In order to design high-performance navigation signals in crowded L frequency band, this paper proposes that some of the signals in L band can use minimum shift keying (MSK) modulation. Firstly, the general mathematical model of minimum shift keying-binary offset carrier (MSK-BOC) modulation is established. Then, simulations about the code tracking error, multipath error envelope, autocorrelation function and power spectral density are performed using the typical navigation signals of GPS L1-CA, GPS L1-P(Y) and GPS L1-M. The results are analyzed and indicate that when the navigation signal meets some requirements, the MSK modulation is better than binary phase shift keying (BPSK) modulation.