中文摘要：

为了在L1频段上有效发射多个高精度的导航信号,GPS全球导航卫星系统设计在同一中心频率上发射多个信号,各信号频谱严重重叠,因此内部干扰成为系统首要考虑问题。通过详细分析GPS L1频段上M码、L1C码、C/A码和P（Y）码的载噪比衰减值,发现除C/A码受到的干扰较严重外,其它三个信号受到的干扰较小,CDMA干扰是主要内部干扰源。分析结果表明,通过有效设计信号参数来减小CDMA干扰,使各信号功率谱主瓣相互错开,并合理设置信号接收功率,可以有效控制系统内干扰。

英文摘要：

As multiple signals are sent from the same center frequency in GPS L1 frequency band to improve bandwidth efficiency and accuracy,interference from different signals transmitted by the same system （ intra-system interference） warrants increasingly careful consideration. The CNR（ carrier-to-noise ratio） degradation of M,L1C,C / A and P （ Y） code signals are computed based on the use of interference coefficients. The simulation results have shown that,under the considered assumptions,C/A code degradation is worse than other signals due to short-code,code division multiple access （ CDMA） interference is preponderant and drives the total intra-system degradation. It is found that codes design solutions, power spectrum envelope design and ground power control can optimize the total intra-system degradation.