一种新型北斗B2频段信号的设计

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AltBOC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AltBOC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。

A New Signal Modulation for Compass B2 Band

AltBOC is the baseline of COMPASS B2 signal modulation.However, AltBOC modulation has drawbacks such as low multiplexing efficiency and great receiver complexity. This paper presents a new modulation type named PS-AltBOC (Phase Shifted AltBOC) with constant envelope 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 30MHz and 150MHz. PS-AltBOC could be a feasible modulation for COMPASS B2 navigation signal.