Radar architecture using MIMO transmit subarrays

Abstract

This paper describes a Multiple Input Multiple Output (MIMO) radar architecture using transmit subarrays. Adapting the size and number of transmit sub-arrays allows optimization of the radar angular resolution, sensitivity, and processing load for a given function. The improved resolution associated with MIMO operation is optimized during volume search where the sub-array beamwidth can be adapted to efficiently fill the search volume, yielding a Signal-to-Noise Ratio (SNR) equivalent to that obtained through conventional operation while improving accuracy. Dedicated track operation does not realize equivalent performance improvement from MIMO operation, but can yield improved accuracy in specific applications. Since a radar system may require a mix of search volumes and dedicated track, the architecture must be flexible. By dynamically choosing the optimal transmit sub-array size to efficiently fill the search volume, increased angular and Doppler resolution can be obtained with a realizable signal processor without sacrificing sensitivity.