Abstract: Timestamped mark of single-pulse zero-crossing of differential response filter is analyzed aiming at the problem of TOA detection accuracy under high SNR(signal-to-noise ratio). Improved differential matching filter based on quadratic decision is proposed. Through zero-crossing distribution, TOA measurement of root mean square error and MLAT system positioning accuracy are employed to verify the improved algorithm in zero-crossing detection accuracy and robustness. Simulation results show that the improved algorithm has higher accuracy of timestamp mark, TOA measurement and initial positioning accuracy. With the increase of SNR of the input signal, the improved square root error of improved algorithm approaches to zero. When the SNR is greater than 20 dB, the accuracy of MLAT system is less than 0.87 m.

Key words: differential matching filter method, timestamp mark, MLAT, positioning performance