Code tracking is necessary for measuring the pseudorange between a navigation satellite and the receiver and subsequently for position and time estimation. In a real receiver, received signal power is generally not known perfectly and must be estimated using the correlation outputs. The code discriminator, whose output should be independent of signal power, must, therefore, be normalized by an estimate of signal power. This article derives the gains and tracking accuracies of normalized coherent and noncoherent early-minus-late code discriminators. The discriminator output variances are computed analytically, or approximated when an analytical expression is not available, and supported by Monte Carlo simulation of the correlation outputs. When the accuracy of the discriminator normalization factor is poor, tracking accuracy and tolerable jammer-to-signal power ratio can be significantly different than if signal power were known perfectly.

中文翻译：

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与信号功率无关的早负晚码鉴别器的跟踪精度


代码跟踪对于测量导航卫星和接收器之间的伪距以及随后的位置和时间估计是必要的。在实际接收器中，接收信号功率通常无法完全获知，必须使用相关输出进行估计。因此，码鉴别器的输出应独立于信号功率，因此必须通过信号功率的估计来标准化。本文推导了归一化相干和非相干早减晚码鉴别器的增益和跟踪精度。鉴别器输出方差通过分析计算，或者在解析表达式不可用时进行近似计算，并由相关输出的蒙特卡罗模拟支持。当鉴别器归一化因子的精度很差时，跟踪精度和可容忍的干扰器与信号功率比可能与完全已知信号功率的情况相比显着不同。