Research On Angle And Range Measurement Method Based On MIMO-OFDM Signal

As the key research areas of intelligent transportation system,vehicle networking need realize the information interaction between the vehicle and the surrounding environment.At the same time,it should have the ability of radar sensing.Since the RF front-end architecture of the vehicle communication system is becoming closer to the radar system,it is worth to study to use the communication signal to realize the function of the radar.Orthogonal frequency division multiplexing(OFDM)as a key technology of radar communication integration system,with which,some achievements have been achieved in the field of distance and velocity measurement of radar;In order to address the problem of angle estimation and positioning,in this paper,focusing on the reasearch of angle and distance estimation method based on MIMO-OFDM signal in the vehicle environment.Firstly,the application scenario and the basic system model of MIMO-OFDM are established.And a interleaving OFDM frame structure is described whereby selected subcarriers will be allocated to selected transmit antennas.Since the subcarriers are orthogonal to each other,the transmitted signal from each antenna element will ideally not experience any coupling or interference from the other subchannels.And the range resolution,which is dependent on the inverse of the bandwidth,will increase with the frame structure.Secondly,in vehicle environment,due to the presence of multipath effect and the transmission signals have the same carrier frequency,it is likely to cause the receiver signal correlated.In order to solve the problem of low spatial resolution caused by signal correlation in angle estimation,a novel DOA measurement approach for coherent and related signal is proposed based on vehicle MIMO-OFDM signal.And the principle and the derivation of this method is described.The simulation results indicate that the proposed method can not only estimate the correlated and uncorrelated signals at the same time,but provides higher resolution performance for coherent sources compared to conventional spatial smoothing algorithms.At last,in order to quickly locate the target,the accurate estimation of the location parameter is an important part of it.A high resolution space-time domain angle and range measurement approach based on the MIMO channel matrix is proposed for MIMO-OFDM system.The approach takes advantage of two one-dimensional(1-D)spatial-MUSIC(S-MUSIC),and a one-dimensional(1-D)temporal-MUSIC(T-MUSIC)and combines temporal filtering and spatial filtering technology;Compared with the traditional algorithm,the approach can accurately estimate the channel parameters such as direction of arrival(DOAs)and delays of frequency-selective MIMO channel,and accurately obtain the angle and distance information of target simultaneously;Furthermore,The proposed approach improves the resolution of parameter estimation,and has good anti-noise performance.