摘要
AltBOC调制信号具备在上下边带承载不同服务的能力,既可独立接收处理单边带信号达到传统BPSK信号性能,也可联合处理实现更高的定位精度,并作为北斗导航系统B2频段的基线.但是AltBOC也有复用效率低调制复杂等缺点.设计了一种新的具有恒包络的调制方式PS-AltBOC（phase shifted AltBOC）,详细阐述了PS-AltBOC的调制原理,给出PS-AltBOC的时域频域表达式,并且与AltBOC对比分析了功率谱密度,抗多径能力,带外损耗性能等.分析结果表明,PS-AltBOC与Alt-BOC具有相似的功率谱密度、抗多径能力、以及码跟踪能力,当接收机前端滤波带宽在30 ～ 150 MHz时,其带外损失小于Alt-BOC调制.仿真结果表明PS-AltBOC可作为北斗B2频段的候选调制方式.
AltBOC is the baseline of COMPASS B2 signal modulation.However,AltBOC modulation has drawbacks such as low multiplexing efficiency and great receiver complexity.A new modulation type named PS-AltBOC （Phase Shifted AltBOC） with constant envelope is presented based on the standard AltBOC modulation.The detail principle of PS-AltBOC is presented and the math expression of PS-AltBOC is derived.Finally the performances of PSD （Power Spectrum Density）,ranging and multipath tracking performance,side-band losses are compared with the AltBOC modulation.Analysis results show that PS-AltBOC has similar spectrum characteristics,ranging and multipath tracking performance with the AltBOC,and the out-of-side loss is lower than AltBOC when the receiver frontend bandwidth between 30 MHz and 150 MHz.PS-AltBOC could be a feasible modulation for COMPASS B2 navigation signal.
出处
《科学技术与工程》
北大核心
2014年第19期243-247,共5页
Science Technology and Engineering
