论文部分内容阅读
为了解决高动态下对GPS信号快速捕获的问题,提出了改进的部分匹配滤波(PMF)和快速傅里叶变换(FFT)相结合的粗捕方法,对其原理和结构进行了分析,并针对其引起的扇贝损失和捕获性能不高的问题,对传统PMF+FFT方法进行加窗处理;考虑到高动态下基于扩展卡尔曼跟踪的方法对捕获后参数的精度要求很高,因此在粗捕的基础上提出了基于线性调频Z变换(CZT)算法的精捕方法,并在GPS信号理论模型和模拟高动态轨迹的基础上,实现了高动态GPS数字中频信号的生成,为进一步加快捕获速度,对于冷启动时提出了一种组合码相关的卫星快速盲搜方法;最后通过MATLAB进行系统仿真实验,验证了所提出的高动态GPS信号粗捕和精捕算法能在加速度为100 g的高动态环境下有约10 Hz的捕获精度。
In order to solve the problem of rapid acquisition of GPS signals under high dynamic conditions, a coarse catching method based on improved partial matching filtering (PMF) and fast Fourier transform (FFT) is proposed, and its principle and structure are analyzed. The problem of scallop loss and acquisition performance is not high, and the traditional PMF + FFT method is windowed. Considering that the method based on extended Kalman tracking in high dynamics requires high precision of the captured parameters, Based on the chirp Z transform (CZT) algorithm of precision capture method, and in the GPS signal model and simulation of high dynamic trajectory, based on the realization of a high dynamic GPS digital intermediate frequency signal generation, in order to further speed up the capture speed , A fast satellite blind search method based on combination code is proposed for cold start. Finally, the system simulation experiment is carried out by MATLAB to verify that the proposed high dynamic GPS signal rough capture and fine capture algorithm can achieve high acceleration of 100 g Dynamic acquisition of about 10 Hz accuracy.