Ambiguity function analysis for the Hybrid MIMO Phased-array Radar

The hybrid MIMO phased array radar, or HMPAR, is a notional concept for a multisensor radar architecture that combines elements of traditional phased-array radar with the emerging technology of multiple-input multiple output (MIMO) radar. A HMPAR comprises a large number, MP, of T/R elements, organized into M subarrays of P elements each. Within each subarray, passive element-level phase shifting is used to steer transmit and receive beams in some desired fashion. Each of the M subarrays are in turn driven by independently amplified phase-coded signals. This paper derives a version of the radar ambiguity function that is appropriate for this radar architecture. The ambiguity function is a function of time delay, Doppler frequency shift, and two or more spatial variables. An illustrative example for a particular MIMO signal set is given.