Communication method and apparatus
Embodiments of this application provide a communication method and an apparatus. A terminal device may measure a downlink reference signal, to obtain third information of a downlink channel. The terminal device may then determine first information and first scenario-related information of the downlink channel based on the third information, and send the first information and the first scenario-related information to a network device. The network device determines second information based on the first scenario-related information and the first information, where the second information may be considered as reconstructed third information. The third information is reconstructed based on the scenario-related information, so that reconstruction precision of the third information can be improved.
1 . An apparatus, comprising one or more circuits, configured to:
receive first information and first scenario-related information of a downlink channel from a terminal device, wherein the first scenario-related information indicates identification information of at least one scenario corresponding to the downlink channel; and
determine, by using a first decoder, second information of the downlink channel based on the first scenario-related information and the first information, wherein
an input of the first decoder is based on the first information and the first scenario-related information; or
an input of the first decoder is based on the first information, wherein the first decoder corresponds to the first scenario-related information.
2 . The apparatus according to claim 1 , wherein the one or more circuits are configured to determine the second information of the downlink channel based on the first scenario-related information and the first information by:
determining the first decoder in at least one decoder based on the first scenario-related information; and
obtaining the second information of the downlink channel based on the first information and the first decoder.
3 . The apparatus according to claim 2 , wherein the one or more circuits are configured to obtain the second information of the downlink channel based on the first information and the first decoder by:
obtaining a first weighting coefficient matrix based on the first information and the first decoder; and
performing space-frequency joint projection inverse transform on a complex coefficient matrix or a complex coefficient vector corresponding to the first weighting coefficient matrix, to determine the second information.
4 . The apparatus according to claim 1 , wherein the second information comprises an eigen-subspace matrix H′ of the downlink channel, and the eigen-subspace matrix H′ of the downlink channel satisfies the following formula:
H
′
=
∑
k
=
1
K
∑
l
=
1
L
C
(
f
dec
-
scen
(
la
)
)
*
U
1
,
k
*
U
2
,
l
*
wherein H′ represents the eigen-subspace matrix H′ of the downlink channel; U 1,k represents a k th column vector in a basis vector set in a spatial domain direction, k=1, . . . , K, the basis vector set in the spatial domain direction comprises K column vectors, and K is a positive integer; U* 2,1 represents a conjugate transpose of an l th column vector in a basis vector set in a frequency domain direction, l=1, . . . , L, the basis vector set in the frequency domain direction comprises L column vectors, and L is a positive integer; la represents the first information; the function ƒ dec-scen (·) represents the first decoder corresponding to the first scenario-related information, and the first decoder is configured to perform decoding based on the first information; and the function C(·) represents an output of the first decoder as a complex coefficient matrix.
5 . The apparatus according to claim 1 , wherein the second information comprises an eigen-subspace matrix H′ of the downlink channel, and the eigen-subspace matrix H′ of the downlink channel satisfies the following formula:
H
′
=
∑
j
=
1
J
C
(
f
d
e
c
-
s
c
e
n
(
l
a
)
)
❘
"\[LeftBracketingBar]"
j
*
U
1
,
j
*
U
2
,
j
*
wherein H′ represents the eigen-subspace matrix H′ of the downlink channel; la represents the first information; the function ƒ dec-scen (·) represents the first decoder corresponding to the first scenario-related information, and the first decoder is configured to perform decoding based on the first information; the function C(·) represents an output of the first decoder as a complex coefficient matrix; C(·)| j represents a j th complex coefficient in the complex coefficient matrix, j=1, . . . , J, the complex coefficient matrix comprises J complex coefficients, J≤K×L, and K and L are positive integers; U 1,j represents a column vector that is in a basis vector set in a spatial domain direction and that corresponds to C(·)| j , and the basis vector set in the spatial domain direction comprises K column vectors; and U* 2,j represents a conjugate transpose of a column vector that is in a basis vector set in a frequency domain direction and that corresponds to C(·)| j , and the basis vector set in the frequency domain direction comprises L column vectors.
6 . The apparatus according to claim 1 , wherein the first scenario-related information indicates N probability values, wherein each of the N probability values correspond to a scenario.
7 . The apparatus according to claim 6 , wherein a sum of the N probability values is less than or equal to 1.
8 . The apparatus according to claim 1 , wherein the one or more circuits are configured to determine second information of the downlink channel based on the first scenario-related information and the first information by:
obtaining a second weighting coefficient matrix based on the first scenario-related information, the first information, and a second decoder; and
performing space-frequency joint projection inverse transform on a complex coefficient matrix or a complex coefficient vector corresponding to the second weighting coefficient matrix, to determine an eigen-subspace matrix H′ of the downlink channel.
9 . The apparatus according to claim 1 , wherein the second information comprises an eigen-subspace matrix H′ of the downlink channel, and the eigen-subspace matrix H′ of the downlink channel satisfies the following formula:
H
′
=
∑
k
=
1
K
∑
l
=
1
L
C
(
f
d
e
c
(
la
,
latents
)
)
*
U
1
,
k
*
U
2
,
l
*
wherein H′ represents the eigen-subspace matrix H′ of the downlink channel; U 1,k represents a k th column vector in a basis vector set in a spatial domain direction, k=1, . . . , K, the basis vector set in the spatial domain direction comprises K column vectors, and K is a positive integer; U* 2,1 represents a conjugate transpose of an l th column vector in a basis vector set in a frequency domain direction, l=1, . . . , L, the basis vector set in the frequency domain direction comprises L column vectors, and L is a positive integer; la represents the first information; latents represents the first scenario-related information, indicating a group of probabilities; the function ƒ dec (·) represents the second decoder, and the second decoder is configured to perform decoding based on the first information and the first scenario-related information; and the function C(·) represents an output of the second decoder as a complex coefficient matrix.
10 . The apparatus according to claim 1 , wherein the second information comprises an eigen-subspace matrix H′ of the downlink channel, and the eigen-subspace matrix H′ of the downlink channel satisfies the following formula:
H
′
=
∑
j
=
1
J
C
(
f
d
e
c
(
la
,
latents
)
)
❘
"\[LeftBracketingBar]"
j
*
U
1
,
j
*
U
2
,
j
*
wherein H′ represents the eigen-subspace matrix H′ of the downlink channel; la represents the first information; latents represents the first scenario-related information, indicating a group of probabilities; the function ƒ dec (·) represents the second decoder, and the second decoder is configured to perform decoding based on the first information and the first scenario-related information; the function C(·) represents an output of the second decoder as a complex coefficient matrix; C(·)| represents a j′h complex coefficient in the complex coefficient matrix, j=1, . . . , J, the complex coefficient matrix comprises J complex coefficients, J≤K×L, and K and L are positive integers; U 1,j represents a column vector that is in a basis vector set in a spatial domain direction and that corresponds to C(·)| j , and the basis vector set in the spatial domain direction comprises K column vectors; and U* 2,j represents a conjugate transpose of a column vector that is in a basis vector set in a frequency domain direction and that corresponds to C(·)| j , and the basis vector set in the frequency domain direction comprises L column vectors.
11 . The apparatus according to claim 1 , wherein the at least one scenario comprises a scenario in which there is a single strong path in two polarization directions.
12 . An apparatus, comprising one or more circuits, configured to:
measure a downlink reference signal received from a network device, to obtain third information of a downlink channel;
determine first information and first scenario-related information of the downlink channel based on the third information, wherein the first information is determined by a first encoder, the first scenario-related information indicates identification information of at least one scenario corresponding to the downlink channel, and wherein
an input of the first encoder is based on the third information and the first scenario-related information; or
an input of the first encoder is based on the third information, wherein the first encoder corresponds to the first scenario-related information; and
send the first information and the first scenario-related information to the network device.
13 . The apparatus according to claim 12 , wherein the one or more circuits are configured to determine the first information and the first scenario-related information of the downlink channel based on the third information by:
determining the first scenario-related information based on the third information;
determining the first encoder in at least one encoder based on the first scenario-related information; and
obtaining the first information based on the third information and the first encoder.
14 . The apparatus according to claim 12 , wherein the one or more circuits are configured to determine the first scenario-related information based on the third information by:
determining the first scenario-related information based on an energy matrix P corresponding to the third information.
15 . The apparatus according to claim 12 , wherein the first scenario-related information indicates N probability values, wherein each of the N probability values correspond to a scenario.
16 . The apparatus according to claim 15 , wherein a sum of the N probability values is less than or equal to 1.
17 . The apparatus according to claim 12 , wherein the at least one scenario comprises a scenario having a rich angle domain and delay domain extension.
18 . A communications method, comprising:
receiving first information and first scenario-related information of a downlink channel from a terminal device, wherein the first scenario-related information indicates identification information of at least one scenario corresponding to the downlink channel; and
determining, by using a first decoder, second information of the downlink channel based on the first scenario-related information and the first information, wherein
an input of the first decoder is based on the first information and the first scenario-related information; or
an input of the first decoder is based on the first information, wherein the first decoder corresponds to the first scenario-related information.
19 . The method according to claim 18 , wherein determining the second information of the downlink channel based on the first scenario-related information and the first information comprises:
determining the first decoder in at least one decoder based on the first scenario-related information; and
obtaining the second information of the downlink channel based on the first information and the first decoder.
20 . The method according to claim 18 , wherein the at least one scenario comprises a line of sight path scenario.