首页>
外国专利>
Method and apparatus for accelerating code correlation searches in initial acquisition and doppler and code phase in re-acquisition of GPS satellite signals
Method and apparatus for accelerating code correlation searches in initial acquisition and doppler and code phase in re-acquisition of GPS satellite signals
展开▼
机译:在GPS卫星信号的初始获取中加速码相关搜索和多普勒以及码相位中的码相关搜索的方法和装置
展开▼
页面导航
摘要
著录项
相似文献
摘要
An embodiment of the present invention is a GPS receiver comprising a GPS downconverter, a fast acquisition unit, a GPS digital signal processor (DSP), a static random access memory (SRAM) and a temperature compensated crystal oscillator (TCXO). The fast acquisition unit samples intermediate frequency signals from the GPS downconverter at 5.17 MHz and writes the samples to the SRAM memory. The memory then supplies the samples back out at a rate of 10.34 MHz. The GPS DSP is such that PRN code and code phase searches are conducted at two times the real- time transmission rate of a GPS satellite. Once a code lock is obtained, Doppler, code, code phase and ephemeris data are stored by a GPS processor. If lock is lost, past code phase and Doppler are projected forward in time using ephemeris and other relevant GPS satellite knowledge to constrain a new search to re-establish lock.
展开▼