摘要
捕获是GPS接收机内信号处理的第一步。捕获过程可以粗略地估算出可见卫星信号载波多普勒频移和码相位,并将估算值传送给后续的跟踪程序。捕获的速度直接决定GPS接收机的性能。基于相关运算的信号捕获算法主要分为时域相关法和基于FFT的循环相关法,因此在基-2FFT循环相关法的基础上提出基-4FFT循环相关法,通过接收真实GPS卫星数据并进行MATLAB仿真分析,最终给出时域相关法、基-2FFT和基-4FFT循环相关法对应的捕获结果与仿真时间。结果表明,在捕获结果相同的前提下,基-4FFT循环相关法的运算速度有所提升。
Acquisition is the first step of signal processing in GPS receiver.The acquisition process can roughly estimate the Doppler frequency shift and the phase of the carrier of the visible satellite signal,and transfer the estimated value to the following tracking program.The performance of GPS receiver can be directly determined by the speed of acquisition.Signal acquisition algorithm based on correlation operation is mainly divided into two aspects including time domain correlation method and cyclic correlation method based on FFT,so this paper presents a cyclic correlation method using radix-4 FFT on the basis of radix-2 FFT,and performance of these acquisition algorithms is compared with time domain correlation method by receiving real GPS satellite signal and MATLAB simulation analysis.The results show that the operation speed of cyclic correlation method using radix-4 FFT is improved while the acquisition results are the same.
出处
《信息技术》
2017年第12期85-89,共5页
Information Technology
基金
陕西省科技统筹创新工程计划战略性新兴产业重大产品(群)项目(2014KTCQ01-21)
陕西省科技统筹创新工程计划项目(2012KTCQ01-06)
国家自然科学基金(61661049)
