Radar Detection Method and Related Apparatus
A radar ranging method includes: obtaining a first signal, where the first signal is a frequency domain signal obtained after low frequency suppression is performed in a beat frequency signal, and the beat frequency signal is a signal obtained by mixing a transmitted signal transmitted by a frequency modulated continuous wave FMCW radar and a received echo signal; performing mean gradient calculation on the first signal in frequency domain to obtain a second signal; and calculating at least one of a speed or a distance of a target object based on a peak signal in the second signal.
1 . A method comprising:
receiving an echo signal;
mixing a signal from a frequency modulated continuous wave (FMCW) radar and the echo signal to obtain a beat frequency signal;
performing low frequency suppression on the beat frequency signal to obtain a first signal;
performing a mean gradient calculation on the first signal in a frequency domain to obtain a second signal, wherein the mean gradient calculation indicates a difference between a first signal value of each sampling point in the first signal and a second signal value of a surrounding sampling point;
determining a peak signal in the second signal; and
calculating at least one of a speed or a distance of a target object based on the peak signal.
2 . The method of claim 1 , wherein performing low frequency suppression on the beat frequency signal to obtain first signal comprises:
performing low frequency suppression on the beat frequency signal to obtain a first transition signal; and
performing a discrete Fourier transform or a short-time Fourier transform on the first transition signal to obtain the first signal.
3 . The method of claim 1 , wherein performing low frequency suppression on the beat frequency signal to obtain the first signal comprises:
performing a discrete Fourier transform or a short-time Fourier transform on the beat frequency signal to obtain a second transition signal; and
performing low frequency suppression on the second transition signal to obtain the first signal.
4 . The method of claim 1 , further comprising performing the low frequency suppression using a digital tap filter, or performing the low frequency suppression by performing scaling processing on a preset sequence parameter.
5 . The method of claim 1 , wherein performing the mean gradient calculation on the first signal in the frequency domain to obtain the second signal comprises performing, in the frequency domain, a target operation on a third signal of each sampling point in a plurality of sampling points in the first signal to obtain a sub-signal of each sampling point that is in the second signal and that corresponds to each of the sampling point, wherein the target operation comprises: performing a difference operation between the first signal value of each sampling point and a reference value to obtain the sub-signal, and wherein the reference value is an average value based on signal values of at least two other sampling points different from the sampling point.
6 . The method of claim 5 , wherein in the frequency domain, a spacing between the at least two other sampling points and the sampling point is greater than a first preset threshold and less than a second preset threshold.
7 . The method of claim 6 , wherein the sub-signal, represented as ΔS(k), of each sampling point is as follows:
Δ S ( k )= S ( k )−(Σ n-1 lw ( S ( k−l p −n )+ S ( k+l p +n )))/(2 l w ),
wherein S(k) is the first signal value of each sampling point, S(k−l p −n) is a third signal value of another sampling point that has a first frequency less than that of each sampling point in the frequency domain and that is separated from each sampling point by (l p +n) sampling points, S(k+l p +n) is a fourth signal value of another sampling point that has a second frequency greater than that of each sampling point in the frequency domain and that is separated from each sampling point by (l p +n) sampling points, l p is the first preset threshold, and l w is the second preset threshold.
8 . 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:
receive an echo signal;
mix a signal from a frequency modulated continuous wave (FMCW) radar and the echo signal to obtain a beat frequency signal;
perform low frequency suppression on the beat frequency signal to obtain a first signal;
perform a mean gradient calculation on the first signal in a frequency domain to obtain a second signal, wherein the mean gradient calculation indicates a difference between a first signal value of each sampling point in the first signal and a second signal value of a surrounding sampling point;
determine a peak signal in the second signal, and
calculate at least one of a speed or a distance of a target object based on the peak signal.
9 . The apparatus of claim 8 , wherein performing low frequency suppression on the beat frequency signal to obtain the first signal comprises:
performing low frequency suppression on the beat frequency signal to obtain a first transition signal; and
performing discrete a Fourier transform or a short-time Fourier transform on the first transition signal to obtain the first signal.
10 . The apparatus of claim 8 , wherein performing low frequency suppression on the beat frequency signal to obtain the first signal comprises:
performing discrete a Fourier transform or a short-time Fourier transform on the beat frequency signal to obtain a second transition signal; and
performing low frequency suppression on the second transition signal to obtain the first signal.
11 . The apparatus of claim 8 , further configured to perform the low frequency suppression using a digital tap filter, or perform the low frequency suppression by performing scaling processing on a preset sequence parameter.
12 . The apparatus of claim 8 , wherein performing the mean gradient calculation on the first signal in the frequency domain to obtain the second signal comprises: performing, in the frequency domain, a target operation on a third signal of each sampling point in a plurality of sampling points in the first signal; to obtain a sub-signal of each sampling point that is in the second signal and that corresponds to each of the sampling point, wherein the target operation comprises: performing a difference operation between the first signal value of each sampling point and a reference value to obtain the sub-signal, and wherein the reference value is an average value based on signal values of at least two other sampling points different from the sampling point.
13 . The apparatus of claim 12 , wherein in the frequency domain, a spacing between the at least two other sampling points and the sampling point is greater than a first preset threshold and less than a second preset threshold.
14 . The apparatus of claim 13 , wherein the sub-signal, represented as ΔS(k), of each sampling point is as follows:
Δ S ( k )= S ( k )−(Σ n-1 lw ( S ( k−l p −n )+ S ( k+l p +n )))/(2 l w ),
wherein S(k) is the first signal value of each sampling point, S(k−l p −n) is a third signal value of another sampling point that has a first frequency less than that of each sampling point in the frequency domain and that is separated from each sampling point by (l p +n) sampling points, S(k+l p +n) is a fourth signal value of another sampling point that has a second frequency greater than that of each sampling point in the frequency domain and that is separated from each sampling point by (l p +n) sampling points, l p is the first preset threshold, and l w is the second preset threshold.
15 . A computer program product comprising computer-executable instructions stormed on a non-transitory computer-readable storage medium, wherein the computer-executable instructions, when executed by a processor of an apparatus, cause the apparatus to:
receive an echo signal;
mix a signal from a frequency modulated continuous wave (FMCW) radar and the echo signal to obtain a beat frequency signal;
perform low frequency suppression on the beat frequency signal to obtain a first signal;
perform a mean gradient calculation on the first signal in a frequency domain to obtain a second signal, wherein the mean gradient calculation indicates a difference between a first signal value of each sampling point in the first signal and a second signal value of a surrounding sampling point;
determine a peak signal in the second signal; and
calculate at least one of a speed or a distance of a target object based on the peak signal.
16 . The computer program product of claim 15 , wherein performing low frequency suppression on the beat frequency signal to obtain the first signal comprises:
performing low frequency suppression on the beat frequency signal to obtain a first transition signal; and
performing a discrete Fourier transform or a short-time Fourier transform on the first transition signal to obtain the first signal.
17 . The computer program product of claim 15 , wherein performing low frequency suppression on the beat frequency signal to obtain the first signal comprises:
performing a discrete Fourier transform or a short-time Fourier transform on the beat frequency signal to obtain a second transition signal; and
performing low frequency suppression on the second transition signal to obtain the first signal.
18 . The computer program product of claim 15 , further configured to perform the low frequency suppression using a digital tap filter, or perform the low frequency suppression by performing scaling processing on a preset sequence parameter.
19 . The computer program product of claim 15 , wherein performing the mean gradient calculation on the first signal in the frequency domain to obtain the second signal comprises performing, in the frequency domain, a target operation on a third signal of each sampling point in a plurality of sampling points in the first signal to obtain a sub-signal of each sampling point that is in the second signal and that corresponds to each sampling point, wherein the target operation comprises performing a difference operation between the first signal value of each sampling point and a reference value to obtain the sub-signal, and wherein the reference value is an average value based on signal values of at least two other sampling points than the sampling point.
20 . The computer program product of claim 19 , wherein in the frequency domain, a spacing between the at least two other sampling points and the sampling point is greater than a first preset threshold and less than a second preset threshold.