【摘要】 GPS信号载波恢复技术是无码GPS测地接收机的主要技术之一。本文通过分析GPS信号的调制特性,研究了无码GPS信号的载波恢复技术。在GPS信号中载波是完全抑制的,尽管接收的GPS频谱中不含载波分量,但它是能够恢复的。平方环和科斯塔环适用于L₂波段载波恢复,而四次方环和斯普里凯尔环适用于L₁波段载波恢复。这些环都采用了窄带和锁相技术。最后本文分析了噪声对锁相误差的影响。更多还原

【Abstract】 Recovering the carrier of GPS signal is one of key techniques for the codeless GPS geodetic receiver. In this paper, the techniques of recovering GPS signal carrier are researched by analyzing the modulation characteristics of GPS signal. The carrier component presented in GPS signal is completely suppressed. Even though the spectrum of the received GPS signal does not contain a carrier component, it is possible to reconstruct one. Both 2nd power loop and Costas loop suitable for suppressed carrier tracking of the GPS L₂ band signal are discussed. And both-4th power loop and Spilkers loop suitable for suppressed carrier tracking of the GPS L₁ band signal are also discussed. In any case, the implemented loop is usually a narrow band and employs the phase—lock principle. The locked phase errors in the presence noise are analyzed.更多还原