基于软件接收机的GPS L2C信号采集与数据处理（英文）

Signal collecting and data processing of GPS L2C based on software receiver

L2C信号是由现代化GPS IIR-M卫星播发的新一代民用信号。基于软件接收机的信号采集与数据处理的研究旨在提高信号在低信噪比环境下的捕获稳定性和跟踪精度。L2C信号结构描述了其民用中码和民用长码的时分复用特征。信号采集部分包括宽频天线和接收机前端的设计,工作频段为L1-L2频段,前端采用下变频和频谱搬移来避免频谱混叠。数据处理中采用降频处理的方法能有效增强信号捕获的稳定性,并利用圆周相关算法获得CM码的初始相位。码和载波跟踪数据处理包含计算原理的介绍和跟踪环结构设计。最后,通过低信噪比环境下的实验来验证L2C信号采集与数据处理方法的有效性。

GPS L2C signal is a new civilian signal launched by the modernized GPS Block IIR-M satellite. The signal collecting and data processing based on software receiver is studied to improve the acquisition stability and tracking precision in low signal-to-noise ratio environment. The signal structure describes the time division multiplexing characteristic of civil moderate and civil long code. The part of signal collecting includes the broadband antenna and the design of front-end. The designed front-end of software receiver working in L1-L2 band applies frequency down conversion and moves the spectrum of the digital signal to avoid aliasing. In data processing, a frequency reduction processing method is put forward to increase the stability of acquisition. Circular correlation algorithm is applied to attain the initial phase of CM code. In the section of code and carrier tracking data processing, the computational principles are introduced and the structure of the tracking loop is designed. Finally, the experiments in low signal-to-noise ratio environment are designed and implemented, which prove the effectiveness of signal receiving and processing. ©, 2014, Editorial Department of Journal of Chinese Inertial Technology. All right reserved.