对GNSS中的BPSK、BOC两种调制方法进行分析，从其时域表达式、功率谱密度函数表达式出发，分析其性能、对码跟踪精度的影响。(The two modulation methods of BPSK and BOC in GNSS are analyzed. From the expressions of time expressions and power spectral density functions, the performance and code tracking accuracy