Research On Multipath Delay Estimation Based On Sparse Iteration Algorithm

As an important parameter estimation method,time delay estimation plays a very significant role in indoor positioning,target monitoring,geological exploration and other fields.Due to the limitation of signal correlation and algorithm grid,the delay estimation technology in dense multipath environment has become the research hotspot and difficulty in this field.The traditional delay estimation methods,such as the subspace class method based on eigenvalue decomposition,improve the performance of time delay estimation,but such methods are easily limited by resolution in dense multipath environment and cannot meet the requirements of high precision estimation.The parameter estimation method based on sparse iteration provides a new solution for the time delay estimation in dense multipath environment.This paper studies the time delay estimation and the joint delay-angle estimation in dense multipath based on the sparse iteration algorithm.The specific work of this paper is as follows:(1)The traditional time delay estimation method can not meet the accuracy requirements in the face of the off-grid problem,this paper designs a sparse iteration time delay estimation method based on covariance,and combines the Chirp signal and OFDM signal model of the two different analyses the algorithm of time delay estimation under different SNRs performance,simulation experiment show that sparse iterative algorithm of time delay estimation has high estimation precision,and is superior to the OMP algorithm.(2)In order to improve the performance of time delay estimation in dense multipath cases,a sparse iterative time delay estimation method based on covariance matrix combined with matched filtering is proposed in this paper.The signal model is changed into a signal model composed of the frequency domain information of transmitted signals.In the validation process,two kinds of signals,Chirp signal and OFDM signal,are used for the experiment,and the experimental comparison with MUSIC,OMP and TD-SPICE?FD-SPICE algorithm verifies the estimation advantage of this method in the dense multipath condition.(3)Aiming at the problem of joint estimation of time delay and angle in dense multipath environment,a time delay and Angle joint estimation method based on frequency domain information is proposed,which combines the theoretical research basis precious mentioned.This algorithm combines the improved joint estimation model with the sparse iterative algorithm to perform two independent parameter estimation.The proposed joint estimation method is compared with the joint estimation method of MUSIC and TD-SPICE.The accuracy of time delay and angle parameter estimation is verified respectively,and the estimation performance of the proposed joint estimation algorithm in the dense multipath environment is analyzed.The numeric computation illustrate the proposed joint estimation algorithm has high estimation accuracy.