带限信道中准相干码相关参考波形技术多径抑制性能分析

Multipath mitigation performance evaluation of quasi-coherent code correlation reference waveform technique in band-limited receiver channels

码相关参考波形(CCRW)技术以其设计灵活、抗多径性能优异等特点成为卫星导航多径抑制研究的热点,但目前相关文献在分析CCRW技术时常假设单边信道带宽无限或远大于扩频码率,且仅研究特定参考波形的性能,缺乏具有工程指导意义的定量结论。根据CCRW技术一般原理,推导了在无限带宽时任意参考波形的鉴别曲线计算公式,给出了满足稳定跟踪的波形约束条件。分析了不同带宽和闸宽参数的W2/W4/W5三类参考波形的准相干多径误差包络性能,仿真表明带限信道中W4、W5波形抗多径性能优于W2波形;以GPS L5和Galileo E5a/E5b的QPSK(10)信号为例进行原理样机试验,结果表明W2、W5算法比窄相关技术的3dB衰减多径误差包络面积减小达63%和72%。结论可用于现代化导航接收机的多径抑制设计。

Code Correlation Reference Waveform has been the research hotspot for its flexibility and outstanding multipath mitigation performance in GNSS receivers.But the analysis from the literature related usually assumes that the single-side bandwidth is infinite or much larger than the chipping rate and only specified waveform has been studied,thus there is a lack of quantitative results for modern band-limited receivers.Based on the CCRW principle,the formulae and design constraints for the discriminator curve of any reference waveform were derived.The multi-path error envelopes of quasi-coherent W2/W4/W5 waveforms were studied.Simulation results indicate that W4/W5 outperforms the W2 algorithm.A QPSK（10） prototype receiver developed for GPS L5 and Galileo E5a/E5b was tested with a GNSS simulator.Compared with Narrow Correlator,the multipath envelope area for a 3dB attenuated multipath signal has been improved by 63% and 72% for W2 and W5 respectively.This research can be used as a guideline for modern GNSS receivers.