Method and apparatus for coded radar signals
Examples disclosed herein relate to a system of object detection, the system including a continuous modulation signal unit to generate a continuous modulation signal, a code generation unit to sample, quantize and encode the continuous modulation signal to generate an encoded signal, a transmit antenna to transmit the encoded signal, and a receive antenna to receive a reflection of the encoded signal and separate the reflection of the encoded signal from other signals.
1. A method for signal generation, comprising:
generating a continuous waveform signal;
encoding the continuous waveform signal as a first signal, wherein the encoding comprises applying a Kasami coding to generate the first signal separable from noise and interfering signals based on the Kasami coding in the first signal, wherein the encoding further comprises generating, via a code control module, a pulse code modulation-type signal in the first signal that enables an identification of a detected object, and wherein the encoding further comprises generating, via a modulation control module, a quantization of the first signal in a form that enables a derivation of a range and velocity of the detected object;
transmitting the first signal from a first transmitter through multiple transmissions in a beam-steering scheme, wherein each transmission of the multiple transmissions is coded differently from other transmissions of the multiple transmissions;
receiving a plurality of signals from a plurality of sources;
isolating a reflection of the first signal from the plurality of signals;
determining a range and a velocity of an object detected by the reflection of the first signal;
comparing received signals to a power threshold to identify direct reflection signals and low power signals; and
comparing low power signals to a reduced power threshold to separate the low power signals from noise signals.
2. The method of claim 1 , wherein the continuous waveform signal is a frequency modulation continuous wave signal.
3. The method of claim 1 , wherein the encoding of the continuous waveform signal as the first signal comprises applying pulse code modulation to generate the first signal.
4. The method of claim 1 , wherein the reflection of the first signal comprises a non-line-of-sight (NLOS) deflection or a multi-hop deflection.
5. The method of claim 1 , wherein the isolating of the reflection of the first signal from the plurality of signals comprises decoding the reflection of the first signal.
6. The method of claim 1 , wherein the isolating of the reflection of the first signal from the plurality of signals further comprises comparing the reflection of the first signal to the power threshold.
7. The method of claim 6 , wherein the isolating of the reflection of the first signal from the plurality of signals further comprises reducing the power threshold for detection of non-line-of-sight (NLOS) objects.
8. The method of claim 1 , wherein the transmitting of the first signal from the first transmitter comprises transmitting the first signal using a metastructure antenna.
9. A method for object detection, comprising:
allocating a code to a radar sensing unit in a vehicle;
encoding a continuous modulation signal with the code, thereby generating a coded signal, wherein the encoding comprises generating, via a code control module, a pulse code modulation-type signal in the coded signal that enables an identification of a detected object, and wherein the encoding further comprises generating, via a modulation control module, a quantization of the coded signal in a form that enables a derivation of a range and velocity of the detected object;
transmitting the coded signal in multiple transmissions during a beam- steering operation of the radar sensing unit, wherein each transmission of the multiple transmissions is coded differently from other transmissions of the multiple transmissions;
receiving a plurality of reflections from a plurality of sources;
filtering the plurality of reflections to isolate the coded signal, wherein the coded signal is encoded with Kasami coding and separable from noise and interfering signals based on the Kasami coding in the coded signal;
detecting an interference signature;
comparing received signals to a power threshold to identify direct reflection signals and low power signals; and
comparing low power signals to a reduced power threshold to separate the low power signals from noise signals.
10. The method of claim 9 , wherein the transmitting of the coded signal is through a metastructure antenna in the radar sensing unit.
11. The method of claim 9 , wherein the filtering of the plurality of reflections to isolate the coded signal comprises comparing the plurality of reflections to the power threshold.
12. The method of claim 11 , wherein the filtering of the plurality of reflections to isolate the coded signal further comprises reducing the power threshold for detection of non-line-of-sight (NLOS) objects.
13. The method of claim 9 , wherein the detecting of the interference signature with the radar sensing unit comprises identifying a signal condition of an environment of the vehicle.