Precision Time Delay Estimation Technique And Its Application In Underwater Acoustic Positioning System

Direct sound identification and extraction technology is the key technology of underwater acoustic positioning system, the technology is also widely used in communications and detection systems. Acoustic positioning technology widely used in fisheries, marine environmental monitoring and oil exploitation. The shallow sea in complex environments multipath interference identification and extraction will affect the performance of the positioning system direct sound.Paper introduces the problems encountered in the classical correlation method copy large amount of computation when platform. To solve this problem of signal down-sampling.Delay Doppler shift for correlation peaks caused by correlation peak instantaneous frequency method, double-pulse method and optimization method to reduce the emission signal delay skew. For the Doppler signal processing gain due to the problem of declining to take a copy of the signal to extend the method to reduce the performance degradation. For channel cross talk and take the edge of the signal windowed input-output ratio using the method of inhibition. Through these measures related to the classical copy exhibited good performance.Classical correlation method can not break delay the resolution of Rayleigh limit, it can not achieve good performance of anti-leak string band in a small interval condition. Therefore,this article studied the delay estimation algorithm high resolution. MUSIC method to solve the problem of high-resolution time delay estimation. Optimized convolution method to solve the high-resolution time delay estimation under conditions of low complexity. Iterative method to solve the problem of delay estimation under multi-user conditions. Compressed sensing has a good delay resolution. Obtain an estimate of non-integer delay and pulse amplitude of virtual bandwidth expansion method. Experimental data to verify the performance of these methods.Finally, since the algorithm needs to be implemented on the platform, it introduces a high-performance graphics platform for high-performance real-time delay estimation.Platform signal processing using frame processing, time delay estimation method to solve the problem using overlapping frame boundary points. Using acoustic field information to solve the problem of the selection pulse.