The Study Of MIMO Radar

The inspiration of MIMO radar comes from the MIMO technique of wireless communication, it uses array antenna both in transmit and receive terminals, transmits orthogonal signals and obtains spatial diversity gain, so it can overcome target RCS scintillations, and has a better performance than traditional radar. There exists three kind of MIMO radar: transmit-receive diversity MIMO radar, transmit diversity MIMO radar, and closely spaced MIMO radar at both transmit and receive terminals. This article introduces these three radars in detail, discusses their capacities such as target detection, DOA estimation, and parameter identification. As a comparison, the article also gives the performance of phased array radar. In the latter part of the article, the author leads out the concept of virtual array elements and adaptive processing of MIMO radar. Transmitting orthogonal signals, MIMO radar produces virtual elements and expends array aperture, this is the key factor that MIMO radar has a better performance. In order to produce more virtual array elements, the papar also did a research on the locating the array elements using genetic algorithm and simulated annealing algorithm. What's more, adaptive techniques is applicable to MIMO radar, the article mentioned three adaptive techniques: CAPON, APES and CAPES. In return, MIMO radar get a better anti-jamming capacity and a higher spectrum resolution. The last part of the paper is the design of the transmit waveform, the common MIMO radar transmits omnidirectional signals, while both theory and experimental proved that a better resolution can be achieved through focusing the transmit power on the interested location.