Simultaneous beamforming and multiple input-multiple output (MIMO) schemes in radar system

1. A radar system, comprising:

a set of transmitters including a first subset of transmitters and a second subset of transmitters, the first and second subsets of transmitters having a transmitter in common; and

a processor coupled to the set of transmitters, the processor configured to:

modulate a first portion of a chirp in a chirp frame according to a first phase;

modulate a second portion of the chirp in the chirp frame according to a second phase;

combine the first and second portions of the chirp to produce a phase-modified chirp; and

instruct the first and second subsets of transmitters to transmit the phase-modified chirp using time division multiple access (TDMA) and by directing radio frequency energy according to a target angle and a target gain.

2. The radar system of claim 1 , wherein:

the processor is configured to instruct the first and second subsets to transmit, using TDMA, additional chirps of the chirp frame.

3. The radar system of claim 2 , wherein the processor is configured to:

receive a signal including the phase-modified chirp; and

perform a Doppler fast Fourier transform (FFT) on the received signal.

4. The radar system of claim 2 , wherein the processor is configured to combine the first and second portions of the chirp to produce the phase-modified chirp based on applying Doppler division multiple access (DDMA).

5. The radar system of claim 4 , wherein the set of transmitters is configured to transmit, using TDMA, DDMA, and beamforming simultaneously, the phase-modified chirp.

6. The radar system of claim 2 , wherein the processor is configured to instruct the first and second subsets to transmit the phase-modified chirp and the additional chirps based on a first pattern.

7. The radar system of claim 6 , wherein the processor is configured to instruct the first and second subsets to transmit the phase-modified chirp and the additional chirps based on a second pattern, wherein the first pattern and the second pattern alternate based on a time duration.

8. A radar method, comprising:

generating, by a processor of a radar system, a chirp frame comprising a plurality of linear frequency modulated chirps;

modulating, by the processor, a first portion of a chirp of the plurality of linear frequency modulated chirps according to a first phase;

modulating, by the processor, a second portion of the chirp in the chirp frame according to a second phase;

combining, by the processor, the first and second portions of the chirp to produce a phase-modified chirp; and

instructing, by the processor, first and second subsets of transmitters, of a set of transmitters of the radar system, to transmit the phase-modified chirp using time division multiple access (TDMA) and by directing radio frequency energy according to a target angle and a target gain, the first and second subsets of transmitters having a transmitter in common;

demodulating, by the processor, a received signal to obtain the chirp based on a difference in phase values of the first phase and the second phase; and

performing a Doppler fast Fourier transform (FFT) on the received signal.

9. The radar method of claim 8 , wherein the radar system is embedded in a vehicle and further comprising detecting, by the processor, an obstacle on a roadway on which the vehicle is driving.

10. The radar method of claim 9 , further comprising:

instructing the first and second subsets of transmitters to transmit additional chirps of the chirp frame using TDMA.

11. The radar method of claim 10 , further comprising:

instructing, by the processor, the first and second subsets to transmit the phase-modified chirp and the additional chirps based on a first pattern.

12. The radar method of claim 11 , further comprising:

instructing, by the processor, the first and second subsets to transmit the phase-modified chirp and the additional chirps based on a second pattern, wherein the first pattern and the second pattern alternate based on a time duration.

13. The radar method of claim 9 , further comprising:

combining, by the processor, the first and second portions of the chirp to produce the phase-modified chirp based on applying Doppler division multiple access (DDMA).

14. The radar method of claim 13 , further comprising:

instructing, by the processor, the set of transmitters to transmit the phase-modified chirp using TDMA, DDMA, and beamforming simultaneously.

15. A non-transitory computer-readable medium storing executable code, which, when executed by a processor, causes the processor to:

identify phase centers of an antenna architecture of a radar system to obtain a virtual element array;

modulate a first portion of a chirp in a chirp frame according to a first phase;

modulate a second portion of the chirp in the chirp frame according to a second phase;

combine the first and second portions of the chirp to produce a phase-modified chirp; and

instruct a set of transmitters of the radar system to transmit the phase-modified chirp by applying time division multiple access (TDMA) based on the phase centers and by directing radio frequency energy according to a target angle and a target gain according to the virtual element array.

16. The computer-readable medium of claim 15 , wherein:

the set of transmitters includes a first subset of transmitters and a second subset of transmitters, the first and second subsets having a transmitter in common, and

the executable code further causes the radar system to instruct the first and second subsets to transmit, using TDMA, the phase-modified chirp and additional chirps of the chirp frame.

17. The computer-readable medium of claim 16 , wherein the executable code further causes the radar system to:

receive a signal including the phase-modified chirp; and

perform a Doppler fast Fourier transform (FFT) on the received signal.

18. The computer-readable medium of claim 16 , wherein the executable code further causes the radar system to combine the first and second portions of the chirp to produce the phase-modified chirp based on applying Doppler division multiple access (DDMA).

19. The computer-readable medium of claim 18 , wherein the executable code further causes the radar system to instruct the set of transmitters to transmit, using TDMA, DDMA, and beamforming simultaneously, the phase-modified chirp.

20. The computer-readable medium of claim 16 , wherein the executable code further causes the radar system to:

instruct the first and second subsets to transmit the phase-modified chirp and the additional chirps based on a first pattern; and

instruct the first and second subsets to transmit the phase-modified chirp and the additional chirps based on a second pattern, wherein the first pattern and the second pattern alternate based on a time duration.