强信号下GNSS接收机前端处理引起的相关损耗

在全球导航卫星系统（GNSS）信号质量监测及GNSS射频（RF）信号模拟器测试等应用中，有用信号功率往往远高于噪声功率。针对二进制相位移位键控（BPSK）和二进制偏移载波（BOC）调制信号，首次研究了这种强信号条件下接收机带限滤波、采样和量化（BSQ）引起的相关损耗。首先分析了不考虑量化作用时由滤波和采样引起的损耗；然后分析了不考虑前端滤波时由量化和采样引起的损耗，推导了相关损耗的解析表达式并得到了量化器的最佳量化间隔；最后，对于滤波、采样、量化共同作用引起的损耗，采用蒙特卡罗方法仿真分析了GPS L1 C/A信号在不同滤波带宽和量化比特数下的归一化相关功率，探讨了根据仿真结果拟合相关损耗解析表达式的方法以简化分析。

Correlation loss caused by GNSS receiver front-end processing for strong signals

In the applications of global navigation satellite system (GNSS) signal quality monitoring and GNSS radio frequency (RF) signal simulator test, the power of the desired GNSS signal usually goes much higher above the noise floor. This paper investigates the correlation power loss of binary phase shife keying (BPSK) and binary offset carrier (BOC) signals caused by band-limiting, sampling and quantization (BSQ) processing under strong signal conditions. Firstly, the correlation power loss caused by band-limiting and sampling without quantization is studied, and then the loss caused by quantization and sampling without band-limiting is analyzed. Consequently the desired signal correlation loss under corresponding conditions is theoretically derived, and the optimal step size of the uniform quantizer with different quantization bit numbers is determined. Finally, for the combined effect of BSQ on the signal correlation power, Monte Carlo simulations are conducted to analyze the normalized correlator power with the configurations of different bandwidths and quantization bit numbers of a GPS L1 C/A receiver, from which a method of fitting an analytical expression of correlation power loss by using the simulation results is explored to simplify the analysis.