MIMO radar: an idea whose time has come

TLDR

MIMO antenna systems can dramatically improve performance by exploiting signal independence, unlike beamforming, and conventional radar treats target scintillations as a nuisance. The study introduces MIMO radar, which exploits target scintillations to enhance radar performance. The system uses a widely spaced transmit array to view the target from multiple aspects and a conventional receive array for direction finding, with performance evaluated by the Cramer‑Rao bound on direction‑finding error. MIMO radar significantly improves direction‑finding accuracy.

Abstract

It has recently been shown that multiple-input multiple-output (MIMO) antenna systems have the potential to improve dramatically the performance of communication systems over single antenna systems. Unlike beamforming, which presumes a high correlation between signals either transmitted or received by an array, the MIMO concept exploits the independence between signals at the array elements. In conventional radar, target scintillations are regarded as a nuisance parameter that degrades radar performance. The novelty of MIMO radar is that it takes the opposite view; namely, it capitalizes on target scintillations to improve the radar's performance. We introduce the MIMO concept for radar. The MIMO radar system under consideration consists of a transmit array with widely-spaced elements such that each views a different aspect of the target. The array at the receiver is a conventional array used for direction finding (DF). The system performance analysis is carried out in terms of the Cramer-Rao bound of the mean-square error in estimating the target direction. It is shown that MIMO radar leads to significant performance improvement in DF accuracy.