【摘要】 高动态GPS接收机中,扩频信号捕获是系统的关键技术。系统的高动态特性即导航卫星和接收机之间径向距离和径向速度的影响,使GPS信号产生相位延迟和多普勒频移,加大了信号捕获的难度。若采用通常的滑动相关法捕获,需要很长的捕获时间。为提高捕获性能,本文分析了一种频域FFT快速捕获方法,对GPS信号进行频域并行捕获,详细介绍了基于FPGA的具体实现,通过高动态GPS信号发生器的辅助实验,缩短了捕获时间,验证了算法的有效性,并给出了改进措施。更多还原

【Abstract】 For the High Dynamic GPS receiver,acquiring of the PN signal is the key technology.The High Dynamic of system,namely the radial distance and rate between the navigation satellite and receiver,makes phase delay and Doppler-frequency,so the problem makes signal acquiring more difficult.Using general method,long time is needed to acquire GPS signal.In order to improve the acquiring performance,a FFT based acquiring method is analyzed,and the design and implementation based on FPGA are introduced in detail.By the experiments based on the high dynamic GPS signal generator,the availability of the method is proved,and at last,improving measures are explained.更多还原