Satellite disciplined crystal oscillator system based on Kalman filter and PI algorithm

Crystal oscillator disciplined system based on digital phase locked loop ( PLL) technology, using satellite signals output 1 Pulse Per Second (1PPS) local oscillator signal tame, so as to obtain high-precision time and frequency standards. Firstly, using MATLAB simulation for GPS tracking signal, through Kalman filtering and application performance analysis, adaptive filtering coefficients obtained crystal tame and dimension; then, in the case of different parameters PI algorithm for the simulation for the existence of a competitive relationship between the various performance indicators to optimize the coefficient of the Proportion Integration (PI) algorithm; finally, combining the Kalma filtering and PI algorithm to filter and adjust phase. The test result shows that, Kalman filtering and PI algorithm combines technology effectively filter out signal noise, the excellent long-term stability characteristics of a standard satellite receiver seconds pulses generated with excellent short-term stability oven controlled crystal characteristics combined, solving local crystal oscillator aging, long term stability in accuracy and poor performance issues, system output frequency accuracy up nanosecond (ns), finally got the short and long term have a high stability, high precision frequency reference and time synchronization standard source.