Co-prime coded (CPC) doppler division multiplexing (DDM) MIMO radar method and system

A method for operating a Doppler Division Multiplexing (DDM) Multiple-Input-Multiple-Output (MIMO) radar system, comprising:

• generating a linear frequency modulation (LFM) chirp signal;
• generating a plurality of DDM transmit signals from the LFM chirp signal with a plurality of DDM transmitter modules, each having a different co-prime coded (CPC) phase offset from the LFM chirp signal;
• receiving, at one or more receive antennas of a receiver module, a target return signal reflected from the plurality of DDM transmit signals by a target;
• mixing the target return signal with the LFM chirp signal at the receiver module to produce an intermediate frequency signal;
• converting the intermediate frequency signal to a digital signal with an analog-to-digital converter at the receiver module;
• processing the digital signal to detect Doppler spectrum peaks in the digital signal;
• and
• applying a CPC decoder to associate each detected Doppler spectrum peak with a corresponding DDM transmitter module, thereby generating a plurality of transmitter-associated Doppler spectrum peak detections.

A radar system comprising:

• a plurality of transmitter modules configured to simultaneously transmit a plurality of Doppler Division Multiplexing (DDM) linear chirp waveforms in a single transmission frame having a fixed pulse repetition frequency (PRF) rate, where each DDM linear chirp waveform is encoded with different co-prime coded (CPC) phase offset using a programmable multi-bit phase rotator so that Doppler spectrum signals of different transmitter modules can be separated in a single transmission frame when there is overlap between spectrums from different transmitter modules;
• at least a first receiver module configured to receive a target return signal reflected from the plurality of DDM linear chirp waveforms by at least one target and to generate a digital signal from the target return signal;
• and
• a radar control processing unit configured to detect Doppler spectrum peaks in the digital signal and to apply CPC decoding to associate each detected Doppler spectrum peak with a corresponding transmitter module, thereby generating a plurality of transmitter-associated Doppler spectrum peak detections.