The Research Of High Precision Time Synchronization Technology Based On Pseudo-code Ranging

The radar plays an irreplaceable role in modern and future electronic warfare, but the original monostatic radar transceiver faces a variety of threats, such as electronic jamming, low altitude penetration, stealth weapons, anti radiation missiles. In contrast, bistatic or multistatic radar system change the way that the traditional monostatic radar system work, receiving station location and transmitting station location are same, by splitting the transmitting and receiving stations. It has aroused people's attention and got the further rapid development and wide application for its strong ability to survive and better detection function. But the multistatic radar system require to maintain strict synchronization time of each station. When the base clock sources are different relative motion exists, inter stations keeping real-time accurate time synchronization is very difficult. So we need an algorithm of producing high precision synchronous pulse in high dynamic environment between non homologous system.The algorithm is based on the synchronous forward pseudo code ranging. At the receiver, it keeps synchronized with carrier dynamics and pseudo-code dynamics so as to measure the signal transmission delay accurately. In this paper, the receiver synchronization algorithms are stated in detail. First of all, the parallel capture algorithm based on FFT gives a rough estimate of carrier doppler and pseudo-code phase. Then the tracking module works, tracking the carrier and the PN code precisely. In this paper, the concrete realization method is given to the loop phase discriminator and loop filter design and the tracking error is analyzed.Each base uses its own clock whose frequency is not completely same, leading that their generating pulses can't be accurately same. In the end of the article, we design a clock error compensation algorithm to eliminate the influence of differential clock bell and adjust the clock cycle pulse position to solve the program. Proven by actual hardware system, a better time synchronization pulse can be generated in high dynamic environment in use of the algorithm and its precision is far superior to the sampling clock precision. Assuming that the relative radial motion rate reaches 200 m/s, the synchronous pulse jitter can be prodused less than 1 ns using 80 MHZ clock.