分析了射频前端带宽与BOC信号自相关函数的关系,研究了射频前端带宽和早迟码间距对S曲线的影响。在规范的TOA误差估计模型框架下,采用非相干延时码跟踪锁定环,推导出非相干延时锁定环理论计算的码跟踪误差与射频前端带宽、早迟码间距、载噪比、积分时间和码环路带宽之间的关系表达式,从而定量地分析了非相干延时锁定环的码跟踪误差。最后对BPSK-R信号和BOC(10,5)信号的码跟踪性能做了比较,比较表明,BOC(10,5)信号的码跟踪性能优于传统的BPSK-R信号,在相同的码跟踪精度条件下,BOC(10,5)比10.23 MHz BPSK-R信号所需要的载噪比约低7 dB,比1.023 MHz BPSK-R信号低15 dB左右。
The relationship between the autocorrelation function of BOC signal and the radio-frequency front-end bandwidth is analyzed,and the influence of radio-frequency front-end bandwidth and spacing between early code and late code on the S curve is studied.Under the canonical model framework of TOA error estimation and with the no-coherent delay lock loop,a quantitative formula which relates the theoretically calculated code tracking error to the RF front-end bandwidth,spacing between early code and late code,carrier to noise ratio,integration time and code loop bandwidth,is derived leading to a quantitative analysis of the code tracking error for non-coherent delay lock loop.Finally,a comparison between the code tracking performance of BPSK-R signal and that of BOC(10,5) signal is made.The comparison shows that the BOC(10,5) signal code tracking performance is indeed superior to that of the traditional BPSK-R signal,and that to achieve the same code tracking accuracy,the required carrier to noise ratio for BOC(10,5) signal is ~7 dB lower than that for 10.23 MHz BPSK-R signal and~15 dB lower than that for 1.023 MHz BPSK-R signal.