MIMO Radar Coding For Resolving Velocity Ambiguity
AssigneeNXP B.V.
InventorFeike Guss Jansen
Life of this patent
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Abstract
An apparatus for resolving velocity ambiguity in a MIMO RADAR includes a plurality of transmit channels and a virtual channel Each transmit channel includes a transmit antenna configured to transmit a plurality of chirps. Each chirp includes a frequency ramp of a transmit frequency of the respective transmit channel. Each transmit channel is orthogonal to another transmit channel and to a virtual transmit channel. A waveform generator is configured to generate a local oscillator (LO) signal for each transmit channel. A frequency offset circuit is configured to modify the LO signal of each transmit channel with a respective frequency offset to generate the respective transmit frequency.
Claims20
A method for resolving velocity ambiguity in a MIMO RADAR comprising:
- storing a plurality of complex values in a two-dimensional memory partitioned with a plurality of rows and a plurality of columns, each row representing a range gate indexed by a range index, each column representing a Doppler gate indexed by a Doppler index, and each Doppler gate further comprising the plurality of complex values indexed by one of a transmitter index and a receiver index, wherein the transmitter index corresponds to one of a plurality of transmitters of the MIMO RADAR and a virtual transmitter, the receiver index corresponds to one of a plurality of receivers of the MIMO RADAR, each range gate defines a distance between the MIMO RADAR and a reflector, and each Doppler gate defines a relative radial velocity between the MIMO RADAR and the reflector;
- for each range gate, performing a Constant False Alarm Rate (CFAR) method on a summation of an absolute value squared of each complex value for each receiver index, to determine a noise power threshold, forming a first vector including complex values for a subset of the Doppler gates, wherein a size of the subset equals a number of chirps divided by a number of the transmitter indices, and forming a second vector of power values by squaring an absolute value of the respective complex values of the first vector;
- and
- correcting a cyclical shift for each transmitter index of the subset of the Doppler gates.
An apparatus for resolving velocity ambiguity in a MIMO RADAR comprising:
- a plurality of transmit channels and a virtual channel, wherein
- each transmit channel comprises a transmit antenna configured to transmit a plurality of chirps, and
- each chirp comprises a frequency ramp of a transmit frequency of the respective transmit channel, and
- each transmit channel is orthogonal to another transmit channel and orthogonal to a virtual transmit channel;
- a waveform generator configured to generate a local oscillator signal (LO) for each transmit channel;
- and
- a frequency offset circuit configured to modify the LO signal of each transmit channel with a respective frequency offset to generate the respective transmit frequency.
A method for resolving velocity ambiguity in a MIMO RADAR comprising:
- generating a plurality of transmit channels and a virtual channel, each transmit channel comprising a plurality of chirps during a coherent processing interval, each chirp generated by ramping a transmit frequency with a frequency ramp;
- and
- offsetting each transmit channel with a respective frequency offset equal to a fraction of an inverse of a duration of the frequency ramp.
Dependencies are inferred from the claim text.