Research On Joint TOA And DOA Estimation Algorithm Of OFDM Signal

In recent years,with the development of wireless LAN research and the development of mobile communication technology,orthogonal frequency division multiplexing(OFDM)technology with its high spectral efficiency,low system complexity,bandwidth and strong expansion,is widely used in 4G networks and WLAN.With the promotion of smart phones and high-speed wireless communication network,location services on the demand for communication networks have gradually turned to 4G networks,and grown rapidly.OFDM signal related to the positioning of research,with broad market prospects.In this paper,OFDM wireless signal is set as the research object,for the positioning of three scenes when the target is stationary or slow motion,rapid movement and multipath environment in three areas,in-depth delay parameter estimation,delay and arrival angle joint estimation study,the specific work is as follows:(1)A new algorithm for finding the MUSIC delay estimation based on propagator method is proposed for the stationary or low speed motion scene.In this scene,the signal bandwidth is stable,and the full rank matrix can be constructed.The covariance matrix of the signal is processed by block and the propagation operator is get.With the propagation operator and noise subspace,the pseudo spectral function including the delay parameter is obtained.Then,the Root-MUSIC is introduced to find the delay estimation.Through the complexity analysis and simulation experiments,it is found that the algorithm can effectively reduce the complexity of MUSIC algorithm,and the simulation results are close to the lower bound of Cramer-Rao.(2)An joint delay and DOA estimation algorithm based on discrete Fourier transform is proposed for the fast moving scene.Based on the existing discrete Fourier transform,the algorithm obtains the signal peak containing the delay parameter information by discrete Fourier transform of the received signal,and then carries on the one-dimensional ESPRIT DOA estimation to the signal,to complete the joint estimation.Through the complexity analysis and simulation experiments,compared with the traditional delay and DOA estimation,the algorithm greatly reduces the computational complexity.(3)Focus on the multi-path channel problem for wireless location,an ESPRIT delay and DOA estimation algorithm based on TK energy operator is proposed.The algorithm uses the feature of TK energy operator is sensitive to the instantaneous signal,reduces the influence of noise on the parameter estimation,and uses the ESPRIT algorithm to suppress the multipath effect and completes the independent estimation of the delay parameter and the DOA parameter.After obtaining the delay and DOA parameters,the array is constructed by the array element to complete the parameter matching calculation.Simulation results show that the algorithm can effectively overcome the multipath effect and have good parameter estimation performance.