Design And Implementation Of High Dynamic Navigation Signal Acquisition Based On PMT-FFT Algorithm

GPS( Global Positioning System) is a new generation of satellite navigation and positioning system, is widely used in civilian and military aspects. The missile, rocket and other big carriers are working in highly dynamic environments, with the presence of large Doppler shift and pseudo- code delay between the larger velocity and acceleration, navigation receiver the received signal and the local signal when the signal is raised to capture the high technical requirements. This paper aimed to capture high dynamic environments navigation signals to discuss the specific contents are as follows :In this paper, the structural characteristics of the first GPS signal is analyzed to establish PMF-FFT acquisition algorithm based on mathematical model study of the basic principles of navigation signal capture on. The algorithm for the scallop loss problems exist, the two methods of data analysis and research zero padding and windowing compensation, effectively eliminating the effects of scallop loss.By establishing a mathematical model navigation signal high dynamic environment, analyze and rate of change of the carrier Doppler shift and pseudo- code delay to study the impact pseudo code delay and Doppler shift of the carrier coherent output brings. On this basis, the capture of the PMF-FFT system to do a detailed analysis of the various design parameters and presents a high dynamic environment based on improved PMF-FFT algorithm capture program, through MATLAB simulation results show good performance of this program capture.Consider FPGA chip resources, proposed hardware can achieve high dynamic capture program. Using top-down design methodology, the whole system is divided into various sub- capture module, and its input stimulus authentication. The improved storage chip matched filter structure reduces resource consumption; adding dual D flip-flop synchronous asynchronous clock domain crossing circuits to solve problems;using high- way input and output intercept for each module port to do the best precision fixed-point quantization process, try achieve resource optimization while ensuring quantify the loss does not affect the performance capture; through the control of the state machine to the various sub-modules together into an organic whole.Finally, the test set up to capture high dynamic closed-loop system. Simulate a variety of high dynamic sports scenes, test results show that this method is suitable for20 g capture high dynamic environments.