Detection method, detection apparatus, and system

1. A method implemented by a detection apparatus, wherein the method comprises:

determining a first frequency point of N frequency points, wherein N is a positive integer greater than 1; and

transmitting a radio signal in a first frequency band of N frequency bands,

wherein the first frequency point is in the first frequency band,

wherein a bandwidth of the first frequency band is a frequency sweep bandwidth of the radio signal,

wherein either:

one of the N frequency bands partially overlaps at least one of other N−1 frequency bands of the N frequency bands, and an absolute value of a difference between lowest frequencies of any two of the N frequency bands is not less than a first threshold (F); or

the N frequency bands have at least one second frequency band that partially overlaps the first frequency band, and an absolute value of a difference between a lowest frequency of each of the at least one second frequency band and a lowest frequency of the first frequency band is not less than F,

wherein F is related to a maximum detection distance, a maximum interference tolerance distance, or a transmit timing moment error, and

wherein F is greater than a first frequency change range (F1) of the radio signal in a first time length (T1).

2. The method of claim 1 , wherein F is greater than or equal to a frequency change range of the radio signal in a first time length (T1), wherein a value of T1 satisfies one of:

T 1= T 2;

T 1= M*T 2;

T 1= T 2+ T 4;

T 1=max( T 2, T 4);

T 1= T 2+ T 3;

T 1= M*T 2+ T 3;

T 1= T 2+ T 3+ T 4; or

T 1=max( T 2, T 4)+ T 3,

wherein T2=2*d max /c, wherein d max is the maximum detection distance, wherein T3 is the transmit timing moment error, wherein T4=dif max /c, wherein dif max is the maximum interference tolerance distance, wherein c is a speed of light, and wherein M is an integer greater than or equal to 2.

3. The method of claim 1 , wherein F and F1 satisfy: F=F1+Δ, and wherein Δ is a predefined constant or a configured constant.

4. The method of claim 1 , wherein the radio signal is transmitted in the first frequency band of the N frequency bands by a first radar of the detection apparatus, and wherein either:

an absolute value of a difference between a lowest frequency of one of the N frequency bands other than the first frequency band and the lowest frequency of the first frequency band is a positive integer multiple of F; or

the N frequency bands have at least one third frequency band used by a second radar of the detection apparatus, the second radar is of a different type and has a different maximum ranging distance than the first radar, and an absolute value of a difference between a lowest frequency of each of the at least one third frequency band and the lowest frequency of the first frequency band is an integer multiple of a second threshold (F′) that is not equal to F.

5. The method of claim 1 , wherein a transmission cycle of the radio signal is T, and wherein the method further comprises further transmitting the radio signal in the first frequency band in a current transmission cycle.

6. The method of claim 5 , further comprising transmitting, in a previous transmission cycle or in a next transmission cycle of the current transmission cycle, the radio signal in a frequency band other than the first frequency band in the N frequency bands, wherein an absolute value of a difference between a lowest frequency of the frequency band and the lowest frequency of the first frequency band is a positive integer multiple of F.

7. The method of claim 1 , further comprising:

selecting a candidate frequency band from the N frequency bands; and

switching from the first frequency band to the candidate frequency band in response to detecting interference on the first frequency band.

8. The method of claim 1 , wherein Q frequency points in the N frequency points are distributed at an equal interval in a frequency domain, and wherein an absolute value of a frequency difference between two adjacent frequency points of the Q frequency points in the frequency domain is F.

9. The method of claim 1 , wherein a frequency of the first frequency point is a lowest frequency of the first frequency band, a highest frequency of the first frequency band, or a center frequency of the first frequency band.

10. The method of claim 1 , wherein the lowest frequencies of the N frequency bands are distributed at an equal interval in a frequency domain.

11. An apparatus comprising:

a memory configured to store program instructions; and

a processor coupled to the memory, wherein the program instructions cause the processor to be configured to:

determine a first frequency point of N frequency points, wherein N is a positive integer greater than 1; and

transmit a radio signal in a first frequency band of N frequency bands,

wherein the first frequency point is in the first frequency band, wherein a bandwidth of the first frequency band is a frequency sweep bandwidth of the radio signal,

wherein either:

one of the N frequency bands partially overlaps at least one of other N−1 frequency bands of the N frequency bands, and an absolute value of a difference between lowest frequencies of any two frequency bands of the N frequency bands is not less than a first threshold (F); or

the N frequency bands have at least one second frequency band that partially overlaps the first frequency band, and an absolute value of a difference between a lowest frequency of each of the at least one second frequency band and a lowest frequency of the first frequency band is not less than F,

wherein F is related to a maximum detection distance, a maximum interference tolerance distance, or a transmit timing moment error, and

wherein F is greater than a first frequency change range (F1) of the radio signal in a first time length (T1).

12. The apparatus of claim 11 , wherein F is greater than or equal to a frequency change range of the radio signal in a first time length (T1), wherein a value of T1 satisfies one of:

T 1= T 2;

T 1= M*T 2;

T 1= T 2+ T 4;

T 1=max( T 2, T 4);

T 1= T 2+ T 3;

T 1= M*T 2+ T 3;

T 1= T 2+ T 3+ T 4; or

T 1=max( T 2, T 4)+ T 3,

wherein T2 is a delay associated with the maximum detection distance, wherein T3 is a transmit timing moment error, wherein T4 is a delay associated with a maximum interference tolerance distance, and wherein M is an integer greater than or equal to 2.

13. The apparatus of claim 11 , wherein the first frequency change range is a product of a transmitted signal slope and T1.

14. The apparatus of claim 11 , wherein either:

an absolute value of a difference between a lowest frequency of one of the N frequency bands other than the first frequency band and the lowest frequency of the first frequency band is a positive integer multiple of F; or

the N frequency bands have at least one third frequency band, and an absolute value of a difference between a lowest frequency of each of the at least one third frequency band and the lowest frequency of the first frequency band is not a positive integer multiple of F.

15. The apparatus of claim 11 , wherein a transmission cycle of the radio signal is T, and wherein the program instructions further cause the processor to be further configured to:

obtain the first frequency band based on F; and

transmit the radio signal in the first frequency band in a current transmission cycle.

16. The apparatus of claim 11 , wherein the N frequency points are predefined.

17. The apparatus of claim 11 , wherein the N frequency points are distributed at an equal interval in a frequency domain, and wherein an absolute value of a frequency difference between two adjacent frequency points in the frequency domain is F.

18. The apparatus of claim 11 , wherein a frequency of the first frequency point is a lowest frequency of the first frequency band, a highest frequency of the first frequency band, or a center frequency of the first frequency band.

19. The apparatus of claim 11 , wherein the lowest frequencies of the N frequency bands are distributed at an equal interval in a frequency domain.

20. A vehicle comprising:

an apparatus comprising:

a memory configured to store instructions; and

a processor coupled to the memory and configured to execute the instructions to cause the apparatus to be configured to:

determine a first frequency point of N frequency points, wherein N is a positive integer greater than 1; and

transmit a radio signal in a first frequency band of N frequency bands,

wherein the first frequency point is in the first frequency band, wherein a bandwidth of the first frequency band is a frequency sweep bandwidth of the radio signal,

wherein either:

one of the N frequency bands partially overlaps at least one of other N−1 frequency bands of the N frequency bands, and an absolute value of a difference between lowest frequencies of any two frequency bands of the N frequency bands is not less than a first threshold (F); or

the N frequency bands have at least one second frequency band that partially overlaps the first frequency band, and an absolute value of a difference between a lowest frequency of each of the at least one second frequency band and a lowest frequency of the first frequency band is not less than F,

wherein F is related to a maximum detection distance, a maximum interference tolerance distance, or a transmit timing moment error, and

wherein F is greater than a first frequency change range (F1) of the radio signal in a first time length (T1).

21. The vehicle of claim 20 , further comprising at least one radar used by the processor of the apparatus to transmit the radio signal from the vehicle, wherein F is greater than or equal to a frequency change range of the radio signal in a first time length (T1), and wherein a value of T1 is based on a time delay (T2) associated with a distance between the at least one radar and a second radar.