Signal processing method and apparatus
View Patent ↗This application discloses signal processing methods and apparatuses, in the field of radar technologies, and may be applied to scenarios such as intelligent transportation (for example, intelligent transportation, assisted driving, or autonomous driving), a smart home, and a robot. In an example method, a first range time-domain signal of a first subband and a second range time-domain signal of a second subband adjacent to the first subband are obtained. The first range time-domain signal and the second range time-domain signal are synthesized and superposed to obtain a third range time-domain signal. A first peak point and a second peak point of the third range time-domain signal are obtained. A constant phase error θ err between the first range time-domain signal and the second range time-domain signal is obtained based on the first peak point and the second peak point.
1 . A signal processing method, comprising:
transmitting, by a radar, radar signals of a plurality of subbands including a first subband and a second subband adjacent to the first subband;
obtaining, by the radar, a first range time-domain signal of the first subband and a second range time-domain signal of the second subband;
synthesizing and superposing, by the radar, the first range time-domain signal and the second range time-domain signal to obtain a third range time-domain signal;
obtaining, by the radar, a first peak point and a second peak point of the third range time-domain signal, wherein the first peak point is a peak point corresponding to a main lobe of the third range time-domain signal, the second peak point is a peak point corresponding to a first side lobe adjacent to a main peak of the third range time-domain signal, and the peak point corresponding to the first side lobe is higher than a peak point corresponding to a second side lobe adjacent to the main peak of the third range time-domain signal;
determining, by the radar, a constant phase error θ err between the first range time-domain signal and the second range time-domain signal based on the first peak point and the second peak point, wherein θ err ∈[0,2π]; and
obtaining, by the radar, a radar imaging map based on the first range time-domain signal, the second range time-domain signal, and the constant phase error θ err .
2 . The method according to claim 1 , wherein
the determining a constant phase error θ err between the first range time-domain signal and the second range time-domain signal based on the first peak point and the second peak point comprises:
determining a residual constant phase error Δθ of the third range time-domain signal based on a difference between the first peak point and the second peak point, wherein the third range time-domain signal is obtained by compensating the constant phase error θ err with a first compensation value θ, Δθ=θ−θ err , Δθ∈[0,2π], and θ∈[0,2π]; and
determining the constant phase error θ err based on the residual constant phase error Δθ and the first compensation value θ.
3 . The method according to claim 2 , wherein when the peak point corresponding to the first side lobe is on the left side of the peak point corresponding to the main lobe, a value range of the residual constant phase error Δθ is [0, π]; or
when the peak point corresponding to the first side lobe is on the right side of the peak point corresponding to the main lobe, a value range of the residual constant phase error Δθ is [π, 2π].
4 . The method according to claim 2 , wherein the determining a residual constant phase error Δθ of the third range time-domain signal based on a difference between the first peak point and the second peak point comprises:
in response to that a difference between the peak point corresponding to the main lobe of the third range time-domain signal and the peak point corresponding to the first side lobe is a minimum value, determining that the residual constant phase error Δθ is π.
5 . The method according to claim 2 , wherein the first range time-domain signal is represented by the following formula:
R
i
(
t
q
)
=
sin
c
(
γ
Tt
q
)
e
-
j
π
γ
Tt
q
;
the second range time-domain signal is represented by the following formula:
R
i
+
1
(
t
q
)
=
sin
c
(
γ
Tt
q
)
e
j
π
γ
Tt
q
e
j
θ
err
;
and
the third range time-domain signal is represented by the following formula:
R
d
(
t
q
;
θ
)
=
(
1
+
e
j
(
θ
-
θ
err
)
)
·
r
1
(
t
q
)
-
j
·
(
1
-
e
j
(
θ
-
θ
err
)
)
·
r
2
(
t
q
)
,
wherein
r 1 (t q )=sin c(2γTt q ), r 2 (t q )=sin c(γTt q )sin(πγTt q ), R d (t q ; θ) represents the third range time-domain signal, R i (t q ) represents a range time-domain signal of an i th subband at a range moment t q , i∈[1, I], I represents a quantity of subbands on which bandwidth synthesis needs to be performed, q∈[1, Q] represents a range discrete sampling moment, Q represents a total range discrete sampling moment, sin c(γTt q ) represents a signal range envelope signal, γ represents a range chirp slope, T represents a radar transmission time period, e jπγTt q represents signal range phase information, and e jθ err represents inter-subband signal range phase error information.
6 . The method according to claim 1 , further comprising:
determining a constant phase error compensation function based on the constant phase error θ err ;
compensating the first range time-domain signal and the second range time-domain signal based on the constant phase error compensation function; and
synthesizing and superposing the compensated first range time-domain signal and the compensated second range time-domain signal to obtain a fourth range time-domain signal.
7 . The method according to claim 1 , wherein before the synthesizing and superposing the first range time-domain signal and the second range time-domain signal to obtain a third range time-domain signal, the method further comprises:
separately performing channel amplitude calibration on the first range time-domain signal and the second range time-domain signal;
rearranging the first range time-domain signal and the second range time-domain signal based on a carrier frequency sequence;
separately compensating intra-subband higher-order phase errors of the first range time-domain signal and the second range time-domain signal; and
compensating a first-order phase error between the first range time-domain signal and the second range time-domain signal.
8 . An apparatus, comprising:
at least one memory configured to store instructions; and
at least one processor coupled to the at least one memory, wherein the instructions are for execution by the at least one processor to cause the apparatus to:
transmit radar signals of a plurality of subbands including a first subband and a second subband adjacent to the first subband;
obtain a first range time-domain signal of the first subband and a second range time-domain signal of the second subband;
synthesize and superposing the first range time-domain signal and the second range time-domain signal to obtain a third range time-domain signal;
obtain a first peak point and a second peak point of the third range time-domain signal, wherein the first peak point is a peak point corresponding to a main lobe of the third range time-domain signal, the second peak point is a peak point corresponding to a first side lobe adjacent to a main peak of the third range time-domain signal, and the peak point corresponding to the first side lobe is higher than a peak point corresponding to a second side lobe adjacent to the main peak of the third range time-domain signal;
determine a constant phase error θ err between the first range time-domain signal and the second range time-domain signal based on the first peak point and the second peak point, wherein θ err ∈[0,2π]; and
obtain a radar imaging map based on the first range time-domain signal, the second range time-domain signal, and the constant phase error θ err .
9 . The apparatus according to claim 8 , wherein
the determine a constant phase error θ err between the first range time-domain signal and the second range time-domain signal based on the first peak point and the second peak point comprises:
determine a residual constant phase error Δθ of the third range time-domain signal based on a difference between the first peak point and the second peak point, wherein the third range time-domain signal is obtained by compensating the constant phase error θ err , with a first compensation value θ, Δθ=θ−θ err , Δθ∈[0,2π], and θ∈[0,2π]; and
determine the constant phase error θ err based on the residual constant phase error 40 and the first compensation value θ.
10 . The apparatus according to claim 9 , wherein when the peak point corresponding to the first side lobe is on the left side of the peak point corresponding to the main lobe, a value range of the residual constant phase error Δθ is [0, π]; or
when the peak point corresponding to the first side lobe is on the right side of the peak point corresponding to the main lobe, a value range of the residual constant phase error Δθ is [π, 2π].
11 . The apparatus according to claim 9 , wherein the determine a residual constant phase error Δθ of the third range time-domain signal based on a difference between the first peak point and the second peak point comprises:
in response to that a difference between the peak point corresponding to the main lobe of the third range time-domain signal and the peak point corresponding to the first side lobe is a minimum value, determining that the residual constant phase error Δθ is π.
12 . The apparatus according to claim 9 , wherein the first range time-domain signal is represented by the following formula:
R
i
(
t
q
)
=
sin
c
(
γ
Tt
q
)
e
-
j
π
γ
Tt
q
;
the second range time-domain signal is represented by the following formula:
R
i
+
1
(
t
q
)
=
sin
c
(
γ
Tt
q
)
e
j
π
γ
Tt
q
e
j
θ
err
;
and
the third range time-domain signal is represented by the following formula:
R
d
(
t
q
;
θ
)
=
(
1
+
e
j
(
θ
-
θ
err
)
)
·
r
1
(
t
q
)
-
j
·
(
1
-
e
j
(
θ
-
θ
err
)
)
·
r
2
(
t
q
)
,
wherein
r 1 (t q )=sin c(2γTt q ), r 2 (t q )=sin c(γTt q )sin(πγTt q ), R d (t q ; θ) represents the third range time-domain signal, R i (t q ) represents a range time-domain signal of an i th subband at a range moment t q , i∈[1, I], I represents a quantity of subbands on which bandwidth synthesis needs to be performed, q∈[1, Q] represents a range discrete sampling moment, Q represents a total range discrete sampling moment, sin c(γTt q ) represents a signal range envelope signal, γ represents a range chirp slope, T represents a radar transmission time period, e jπγTt q represents signal range phase information, and e jθ err represents inter-subband signal range phase error information.
13 . The apparatus according to claim 8 , wherein the instructions are for execution by the at least one processor to cause the apparatus to:
determine a constant phase error compensation function based on the constant phase error θ err ;
compensate the first range time-domain signal and the second range time-domain signal based on the constant phase error compensation function; and
synthesize and superpose the compensated first range time-domain signal and the compensated second range time-domain signal to obtain a fourth range time-domain signal.
14 . The apparatus according to claim 8 , wherein the instructions are for execution by the at least one processor to cause the apparatus to:
separately perform channel amplitude calibration on the first range time-domain signal and the second range time-domain signal;
rearrange the first range time-domain signal and the second range time-domain signal based on a carrier frequency sequence;
separately compensate intra-subband higher-order phase errors of the first range time-domain signal and the second range time-domain signal; and
compensate a first-order phase error between the first range time-domain signal and the second range time-domain signal.
15 . A non-transitory computer-readable storage media comprising instructions which, when executed by one or more processors of a radar, cause the one or more processors to perform operations comprising:
transmitting radar signals of a plurality of subbands including a first subband and a second subband adjacent to the first subband;
obtaining a first range time-domain signal of the first subband and a second range time-domain signal of the second subband;
synthesizing and superposing the first range time-domain signal and the second range time-domain signal to obtain a third range time-domain signal;
obtaining a first peak point and a second peak point of the third range time-domain signal, wherein the first peak point is a peak point corresponding to a main lobe of the third range time-domain signal, the second peak point is a peak point corresponding to a first side lobe adjacent to a main peak of the third range time-domain signal, and the peak point corresponding to the first side lobe is higher than a peak point corresponding to a second side lobe adjacent to the main peak of the third range time-domain signal;
determining a constant phase error θ err between the first range time-domain signal and the second range time-domain signal based on the first peak point and the second peak point, wherein θ err ∈[0,2π]; and
obtaining a radar imaging map based on the first range time-domain signal, the second range time-domain signal, and the constant phase error θ err .
16 . The non-transitory computer-readable storage media according to claim 15 , wherein the determining a constant phase error θ err , between the first range time-domain signal and the second range time-domain signal based on the first peak point and the second peak point comprises:
determining a residual constant phase error Δθ of the third range time-domain signal based on a difference between the first peak point and the second peak point, wherein the third range time-domain signal is obtained by compensating the constant phase error θ err with a first compensation value θ, Δθ=θ−θ err , Δθ∈[0,2π], and θ∈[0,2π]; and
determining the constant phase error θ err based on the residual constant phase error Δθ and the first compensation value θ.
17 . The non-transitory computer-readable storage media according to claim 16 , wherein when the peak point corresponding to the first side lobe is on the left side of the peak point corresponding to the main lobe, a value range of the residual constant phase error Δθ is [0, π]; or
when the peak point corresponding to the first side lobe is on the right side of the peak point corresponding to the main lobe, a value range of the residual constant phase error Δθ is [π, 2π].
18 . The non-transitory computer-readable storage media according to claim 16 , wherein the determining a residual constant phase error Δθ of the third range time-domain signal based on a difference between the first peak point and the second peak point comprises:
in response to that a difference between the peak point corresponding to the main lobe of the third range time-domain signal and the peak point corresponding to the first side lobe is a minimum value, determining that the residual constant phase error Δθ is π.
19 . The non-transitory computer-readable storage media according to claim 16 , wherein the first range time-domain signal is represented by the following formula:
R
i
(
t
q
)
=
sin
c
(
γ
Tt
q
)
e
-
j
π
γ
Tt
q
;
the second range time-domain signal is represented by the following formula:
R
i
+
1
(
t
q
)
=
sin
c
(
γ
Tt
q
)
e
j
π
γ
Tt
q
e
j
θ
err
;
and
the third range time-domain signal is represented by the following formula:
R
d
(
t
q
;
θ
)
=
(
1
+
e
j
(
θ
-
θ
err
)
)
·
r
1
(
t
q
)
-
j
·
(
1
-
e
j
(
θ
-
θ
err
)
)
·
r
2
(
t
q
)
,
wherein
r 1 (t q )=sin c(2γTt q ), r 2 (t q )=sin c(γTt q ) sin c(πγTt q ), R d (t q ; θ) represents the third range time-domain signal, R i (t q ) represents a range time-domain signal of an i th subband at a range moment t q , i∈[1, I], I represents a quantity of subbands on which bandwidth synthesis needs to be performed, q∈[1, Q] represents a range discrete sampling moment, Q represents a total range discrete sampling moment, sin c(γTt q ) represents a signal range envelope signal, γ represents a range chirp slope, T represents a radar transmission time period, e jπγTt q represents signal range phase information, and e jπ err represents inter-subband signal range phase error information.
20 . The non-transitory computer-readable storage media according to claim 15 , the operations further comprising:
determining a constant phase error compensation function based on the constant phase error θ err ;
compensating the first range time-domain signal and the second range time-domain signal based on the constant phase error compensation function; and
synthesizing and superposing the compensated first range time-domain signal and the compensated second range time-domain signal to obtain a fourth range time-domain signal.