Research On Moving Target Detection With FDA-MIMO Radar

Frequency diverse array(FDA)refers to applying a frequency increment across ad-jacent elements of a phased array(PA),which allows its beam to contain the informa-tion about distance.Combining FDA radar with Multiple Input Multiple Output(MIMO)technology results in the concept of FDA-MIMO radar.Moving target detection is always the focus of radar research.Therefore,this thesis focuses on this problem from aspects:conventional speed moving target detection,high speed target detection and velocity am-biguity resolution methods.The main contents are summarized as follows:(1)The transmitted signal model and echo signal model based on FDA-MIMO radar are derived and compared with conventional MIMO radar with waveform diversity.Then the differences between them are analyzed.(2)Ignoring the effect of frequency increment on signal Doppler frequency,the detec-tion method of conventional speed moving target based on FDA-MIMO radar is studied.The detector with or without secondary data by using the method of generalized likelihood ratio test(GLRT)is derived,and the initial distance,velocity and azimuth of the moving target are estimated.The simulation results show that the performance of target detection and parameter estimation with secondary data is usually better than that without secondary data.(3)High-speed moving target detection methods based on FDA-MIMO radar are studied.After solving the distance migration by using the Keystone transform,in order to suppress the effect of frequency increment on signal Doppler frequency,a time-domain resampling combined with generalized likelihood ratio method is proposed to realize the detection of high-speed moving targets and the estimation of target parameters.Besides,a speed search combined with generalized likelihood ratio test method is proposed to de-tect high-speed moving targets under the background of Gaussian white noise.And the effectiveness of the proposed methods is verfied by computer simulations.(4)For solving the Doppler ambiguity problem of high-speed moving targets in Gaus-sian white noise background,direct search algorithms and a fast algorithm of resolving Doppler ambiguity are proposed.Different from the traditional methods of resolving ve-locity ambiguity,these methods do not require the FDA-MIMO radar to transmit different pulse repetition frequency signals,only use the characteristics of multi-carrier frequency signals transmitted by FDA-MIMO radar.The simulation results show that when the signal-to-noise ratio(SNR)is high,the fast algorithm of resolving Doppler ambiguity can achieve almost the same performance as the direct search algorithms with higher compu-tation.