混合二进制偏移载波调制技术

针对即将在全球卫星导航定位系统GPS的L1民用信号和伽利略卫星导航定位系统的L1开放服务信号中使用的BOC调制技术的优化问题,对MBOC调制技术的基本概念作了重点介绍.并在此基础上用仿真方法验证MBOC(6,1,1/11)信号的多径误差和Gabor带宽,给出仿真结果,同时与BOC信号作比较.仿真结果表明:在采用正弦副载波时,MBOC(6,1,1/11)信号的抗多径性能相对于BOC(1,1)信号和BOC(2,2)信号有明显改善;但在采用余弦副载波时,MBOC(6,1,1/11)信号的抗多径性能相对于BOC(2,2)信号没有明显改善,并且BOC(2,2)信号在Gabor带宽方面还要优于MBOC(6,1,1/11),而BOC信号接收机结构的实现却更加容易.因此,余弦副载波类型的BOC(2,2)相对于MBOC(6,1,1/11)更有优势.

MBOC Modulation in Future GNSS

In future Global Navigation Satellite System(GNSS), GPS and Galileo would take Binary Offset Carrier(BOC) modulation in L1 Civil signal used in GPS and L1 Open Service signal used in Galileo. Multiplexed Binary Offset Carrier(MBOC) modulation seemed to be the most promising optimal way to get better performance for both systems. This paper analysed MBOC modulation in several aspects compared with BOC modulation, such as subcarrier waveform, power spectral density and autocorrelation function, added with simulation results in multipatherror and Gabor bandwidth. The results showed that if the subcarrier was sine type, MBOC(6,1,1/11) signal could easier obtain better antimultipatherror performance than BOC(1,1) signal and BOC(2,2) signal especially when the delay between direct and indirect paths was within 180m; and if the subcarrier was cosine type, MBOC(6,1,1/11) signal was as much as BOC(2,2) signal in antimultipatherror performance. When the subcarrier was cosine type, BOC(2,2) was more compatible than MBOC(6,1,1/11) because of its simplicity of receiver architecture implementation.