Method for controlling radar frequency hopping, apparatus, radar speed measurement method, and radar

1 . A method for controlling radar frequency hopping, comprising:

determining start frequencies of a plurality of frequency-modulated continuous waves (FMCWs) based on a first function such that a difference between the start frequencies of any two adjacent FMCWs in a transmission sequence is greater than a first threshold, wherein the first function is:

b

k

=

β

+

α

-

β

k

,

k

=

1

,

2

,

…

⁢

M

,

 wherein M is an integer ≥2,

wherein b k is a start frequency of the k th FMCW, k is a sequence number of each FMCW, α, β are frequency hopping parameters, and M is a quantity of the plurality of FMCWs, and wherein the first threshold is based on a preconfigured rule; and

controlling a radar to sequentially transmit the plurality of FMCWs by performing frequency hopping based on the start frequencies.

2 . The method of claim 1 , wherein the preconfigured rule ensures that the start frequencies can hop up as much as possible to maximize a separation between the start frequencies within an operating bandwidth of the radar.

3 . The method of claim 1 , wherein the quantity of the plurality of FMCWs is a power of 2.

4 . The method of claim 1 , wherein values of M, α, and β in the first function are limited based on the first threshold.

5 . The method of claim 1 , wherein the plurality of FMCWs constitute one detection subframe, wherein a plurality of detection subframes constitute one detection frame, and wherein the plurality of detection subframes in a detection frame use a same first function to determine the start frequencies of a plurality of FMCWs comprised in each of the plurality of detection subframes.

6 . The method of claim 1 , further comprising:

detecting an interference signal; and

controlling the radar to sequentially transmit the plurality of FMCWs in response to detecting the interference signal.

7 . A radar speed measurement method, comprising:

determining start frequencies using a first function such that a difference between the start frequencies of any two adjacent frequency-modulated continuous waves (FMCWs) in a plurality of FMCWs in a transmission sequence is greater than a first threshold, wherein the first function is:

b

k

=

β

+

α

-

β

k

,

k

=

1

,

2

,

…

⁢

M

,

 wherein M is an integer ≥2,

wherein b k is a start frequency of the k th FMCW, k is a sequence number of each FMCW, α, β are frequency hopping parameters, and M is a quantity of the plurality of FMCWs;

controlling a radar to sequentially transmit the plurality of FMCWs to a target by performing frequency hopping based on the start frequencies;

receiving a reflected signal reflected back by the target in response to the FMCWs; and

calculating a relative speed of the target relative to the radar based on the reflected signal.

8 . The radar speed measurement method of claim 7 , wherein the plurality of FMCWs constitute one detection subframe, wherein a plurality of detection subframes constitute one detection frame, wherein the plurality of detection subframes in a detection frame use a same first function to determine the start frequencies of the plurality of FMCWs comprised in each of the plurality of detection subframes, and wherein the calculating the relative speed comprises:

performing a first fast Fourier transform on first echo intermediate frequency signals corresponding to the plurality of FMCWs in at least one detection subframe to obtain a first speed parameter;

performing a second fast Fourier transform on second echo intermediate frequency signals corresponding to at least one group of a plurality of FMCWs in the detection frame that have a same start frequency to obtain a second speed parameter; and

calculating the relative speed based on the first speed parameter and the second speed parameter.

9 . The radar speed measurement method of claim 8 , wherein the calculating comprises

performing equivalent expansion on a second speed measurement range of the second speed parameter; and

performing matching calculation on the second speed measurement range and a first speed measurement range of the first speed parameter to obtain the relative speed.

10 . The radar speed measurement method of claim 7 , wherein the preconfigured rule ensures that the start frequencies can hop up as much as possible to maximize a separation between the start frequencies within an operating bandwidth of the radar.

11 . The radar speed measurement method of claim 7 , wherein the quantity of the plurality of FMCWs is a power of 2.

12 . The radar speed measurement method of claim 7 , wherein values of M, α, and β in the first function are limited based on the first threshold.

13 . The radar speed measurement method of claim 7 , further comprising performing the frequency hopping based on the start frequencies when an interference signal is detected.

14 . A radar comprising:

a memory configured to store instructions; and

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

sequentially transmit a plurality of frequency-modulated continuous waves (FMCWs) to a target by performing frequency hopping based on start frequencies determined using a first function such that a difference between the start frequencies of any two adjacent FMCWs in a transmission sequence is greater than a first threshold, wherein the first function is:

b

k

=

β

+

α

-

β

k

,

k

=

1

,

2

,

…

⁢

M

,

 wherein M is an integer ≥2,

wherein b k is a start frequency of the k th FMCW, k is a sequence number of each FMCW, α, β are frequency hopping parameters, and M is a quantity of the plurality of FMCWs, and wherein the first threshold is based on a preconfigured rule;

receive a reflected signal reflected back from the target; and

calculate a relative speed of the target relative to the radar based on the reflected signal.

15 . The radar of claim 14 , wherein the plurality of FMCWs constitute one detection subframe, and a plurality of detection subframes constitute one detection frame, wherein the plurality of detection subframes in a detection frame use a same first function to determine the start frequencies of the plurality of FMCWs comprised in each of the plurality of detection subframes, and wherein the processor is further configured to execute the instructions to cause the radar to:

perform a first fast Fourier transform on first echo intermediate frequency signals corresponding to the plurality of FMCWs in at least one detection subframe to obtain a first speed parameter;

perform a second fast Fourier transform on second echo intermediate frequency signals corresponding to at least one group of a plurality of FMCWs in the detection frame that have a same start frequency to obtain a second speed parameter; and

calculate the relative speed based on the first speed parameter and the second speed parameter.

16 . The radar of claim 15 , wherein the processor is further configured to execute the instructions to cause the radar to perform equivalent expansion on a second speed measurement range of the second speed parameter, and perform matching calculation on the second speed measurement range and a first speed measurement range of the first speed parameter to obtain the relative speed.

17 . The radar of claim 14 , wherein the preconfigured rule ensures that the start frequencies can hop up as much as possible to maximize a separation between the start frequencies within an operating bandwidth of the radar.

18 . The radar of claim 14 , wherein the quantity of the plurality of FMCWs is a power of 2.

19 . The radar of claim 14 , wherein values of M, α, and β in the first function are limited based on the first threshold.

20 . The radar of claim 14 , wherein the processor is further configured to execute the instructions to cause the radar to perform the frequency hopping based on the start frequencies when an interference signal is detected.