Signal transmission method and device
Embodiments of the present invention provide a signal transmission method and device. The method includes: determining, by a sending device, a target precoding matrix V, where V=(H) −1 ·{tilde over (H)}, H indicates a channel matrix between the sending device and a receiving device, {tilde over (H)} indicates an equivalent channel matrix between the sending device and the receiving device, ({tilde over (H)} H ·{tilde over (H)}) or ({tilde over (H)}·{tilde over (H)} H ) is a diagonal matrix, and {tilde over (H)} is related to a transmission distance D between the sending device and the receiving device and an element spacing of an antenna of the receiving device; and sending, by the sending device, a signal to the receiving device according to the target precoding matrix V. Because {tilde over (H)} meets a characteristic that ({tilde over (H)} H ·{tilde over (H)}) or ({tilde over (H)}·{tilde over (H)} H ) is a diagonal matrix, a channel corresponding to {tilde over (H)} can support multiple data stream transmission. Therefore, the signal transmission method and device provided in the embodiments of the present invention can support multiple data stream transmission.
1. A signal transmission method, comprising:
determining, by a sending device, a target precoding matrix V, wherein V=(H) −1 ·{tilde over (H)}, H indicates a channel matrix between the sending device and a receiving device, {tilde over (H)} indicates an equivalent channel matrix between the sending device and the receiving device, ({tilde over (H)} H ·{tilde over (H)}) or ({tilde over (H)}·{tilde over (H)} H ) is a diagonal matrix, and {tilde over (H)} is related to a transmission distance D between the sending device and the receiving device and an element spacing of an antenna of the receiving device;
sending, by the sending device, a signal to the receiving device according to the target precoding matrix V; and
implementing multiple data stream transmission between the sending device and the receiving device.
2. The method according to claim 1 , wherein the determining, by a sending device, a target precoding matrix V comprises:
determining, by the sending device, the equivalent channel matrix {tilde over (H)} according to the transmission distance D and the element spacing of the antenna of the receiving device; and
determining, by the sending device, the target precoding matrix V according to H and {tilde over (H)}.
3. The method according to claim 2 , wherein the determining, by the sending device, the equivalent channel matrix {tilde over (H)} according to the transmission distance D and the element spacing of the antenna of the receiving device comprises:
determining, by the sending device, an equivalent element spacing of an antenna of the sending device according to the transmission distance D and the element spacing of the antenna of the receiving device; and
determining, by the sending device, the equivalent channel matrix {tilde over (H)} according to the equivalent element spacing of the antenna of the sending device, the element spacing of the antenna of the receiving device, and the transmission distance D.
4. The method according to claim 3 , wherein the determining, by the sending device, an equivalent element spacing of an antenna of the sending device according to the transmission distance D and the element spacing of the antenna of the receiving device comprises:
determining, by the sending device, an equivalent element spacing s g of the antenna of the sending device according to the transmission distance D and the element spacing of the antenna of the receiving device, wherein s g meets the following formula:
s
g
s
2
=
(
p
+
1
max
(
N
t
,
N
r
)
)
D
λ
sin
θ
sin
ω
,
wherein
s 2 is the element spacing of the antenna of the receiving device, D is the transmission distance D, P is a constant, λ is a wavelength, N t is a quantity of elements included in the antenna of the sending device, N r is a quantity of elements included in the antenna of the receiving device, θ indicates an angle between the antenna of the sending device and a projection that is of the antenna of the sending device and that is on a reference plane, and ω indicates an angle between the antenna of the receiving device and a projection that is of the antenna of the receiving device and that is on the reference plane.
5. The method according to claim 2 , wherein before the determining, by the sending device, the equivalent channel matrix {tilde over (H)} according to the transmission distance D and the element spacing of the antenna of the receiving device, the method further comprises:
receiving, by the sending device, an indication message that is sent by the receiving device and that is used to indicate the transmission distance D.
6. A signal transmission method, comprising:
determining, by a receiving device, a target precoding matrix V, wherein V=(H) −1 ·{tilde over (H)}, H indicates a channel matrix between a sending device and the receiving device, {tilde over (H)} indicates an equivalent channel matrix between the sending device and the receiving device, {tilde over (H)} meets that ({tilde over (H)} H ·{tilde over (H)}) or ({tilde over (H)}·{tilde over (H)} H ) is a diagonal matrix, and {tilde over (H)} is related to a transmission distance D between the sending device and the receiving device and an element spacing of an antenna of the receiving device; and
sending, by the receiving device to the sending device, an indication message used to indicate the target precoding matrix V, so that the sending device sends a signal to the receiving device according to the target precoding matrix V; and
implementing multiple data stream transmission between the sending device and the receiving device.
7. The method according to claim 6 , wherein the determining, by a receiving device, a target precoding matrix V comprises:
determining, by the receiving device, {tilde over (H)} according to the transmission distance D and the element spacing of the antenna of the receiving device; and
determining, by the receiving device, the target precoding matrix V according to {tilde over (H)} and H.
8. The method according to claim 7 , wherein the determining, by the receiving device, {tilde over (H)} according to the transmission distance D and the element spacing of the antenna of the receiving device comprises:
determining, by the receiving device, an equivalent element spacing of an antenna of the sending device according to the transmission distance D and the element spacing of the antenna of the receiving device; and
determining, by the receiving device, {tilde over (H)} according to the equivalent element spacing of the antenna of the sending device, the element spacing of the antenna of the receiving device, and the transmission distance D.
9. The method according to claim 8 , wherein the determining, by the receiving device, an equivalent element spacing of an antenna of the sending device according to the transmission distance D and the element spacing of the antenna of the receiving device comprises:
determining, by the receiving device, an equivalent element spacing s g of the antenna of the sending device according to the transmission distance D and the element spacing of the antenna of the receiving device, wherein s g meets the following formula:
s
g
s
2
=
(
p
+
1
max
(
N
t
,
N
r
)
)
D
λ
sin
θ
sin
ω
,
wherein
s 2 is the element spacing of the antenna of the receiving device, D is the transmission distance D, P is a constant, λ is a wavelength, N t is a quantity of elements included in the antenna of the sending device, N r is a quantity of elements included in the antenna of the receiving device, θ indicates an angle between the antenna of the sending device and a projection that is of the antenna of the sending device and that is on a reference plane, and ω indicates an angle between the antenna of the receiving device and a projection that is of the antenna of the receiving device and that is on the reference plane.
10. The method according to claim 7 , wherein before the determining, by the receiving device, {tilde over (H)} according to the transmission distance D and the element spacing of the antenna of the receiving device, the method further comprises:
receiving, by the receiving device, an indication message that is sent by the sending device and that is used to indicate the transmission distance D.
11. A signal transmission device, comprising:
a processor, configured to determine a target precoding matrix V, wherein V=(H) −1 ·{tilde over (H)}, H indicates a channel matrix between the device and a receiving device, {tilde over (H)} indicates an equivalent channel matrix between the device and the receiving device, ({tilde over (H)} H ·{tilde over (H)}) or ({tilde over (H)}·{tilde over (H)} H ) is a diagonal matrix, and {tilde over (H)} is related to a transmission distance D between the device and the receiving device and an element spacing of an antenna of the receiving device; and
a transmitter, configured to send a signal to the receiving device according to the target precoding matrix V determined by the processor; and
the processor is further configured to implement multiple data stream transmission between the device and the receiving device.
12. The device according to claim 11 , wherein the processor, further configured to determine the equivalent channel matrix {tilde over (H)} according to the transmission distance D and the element spacing of the antenna of the receiving device; and
the processor, further configured to determine the target precoding matrix V according to {tilde over (H)} determined by the processor and H.
13. The device according to claim 12 , wherein the processor, further configured to determine an equivalent element spacing of an antenna of the device according to the transmission distance D and the element spacing of the antenna of the receiving device; and
the processor, further configured to determine the equivalent channel matrix {tilde over (H)} according to the equivalent element spacing that is of the antenna of the device and that is determined by the processor, the element spacing of the antenna of the receiving device, and the transmission distance D.
14. The device according to claim 13 , wherein the processor is further configured to determine an equivalent element spacing s g of the antenna of the device according to the transmission distance D and the element spacing of the antenna of the receiving device, and s g meets the following formula:
s
g
s
2
=
(
p
+
1
max
(
N
t
,
N
r
)
)
D
λ
sin
θ
sin
ω
,
wherein
s 2 is the element spacing of the antenna of the receiving device, D is the transmission distance D, P is a constant, λ is a wavelength, N t is a quantity of elements included in the antenna of the device, N r is a quantity of elements included in the antenna of the receiving device, θ indicates an angle between the antenna of the device and a projection that is of the antenna of the device and that is on a reference plane, and ω indicates an angle between the antenna of the receiving device and a projection that is of the antenna of the receiving device and that is on the reference plane.
15. The device according to claim 12 , wherein the receiver, further configured to: before the processor determines the equivalent channel matrix {tilde over (H)}, receive an indication message that is sent by the receiving device and that is used to indicate the transmission distance D.
16. A signal transmission device, comprising:
a processor, configured to determine a target precoding matrix V, wherein V=(H) −1 ·{tilde over (H)}, H indicates a channel matrix between a sending device and the device, {tilde over (H)} indicates an equivalent channel matrix between the sending device and the device, {tilde over (H)} meets that ({tilde over (H)} H ·{tilde over (H)}) or ({tilde over (H)}·{tilde over (H)} H ) is a diagonal matrix, and {tilde over (H)} is related to a transmission distance D between the sending device and the device and an element spacing of an antenna of the device;
a transmitter, configured to send, to the sending device, an indication message used to indicate the target precoding matrix V determined by the processor; and
the processor is further configured to implement multiple data stream transmission between the sending device and the device.
17. The device according to claim 16 , wherein the processor, further configured to determine {tilde over (H)} according to the transmission distance D and the element spacing of the antenna of the device; and
the processor, further configured to determine the target precoding matrix V according to {tilde over (H)} determined by the processor and H.
18. The device according to claim 17 , wherein the processor, further configured to determine an equivalent element spacing of an antenna of the sending device according to the transmission distance D and the element spacing of the antenna of the device; and
the processor, further configured to determine {tilde over (H)} according to the equivalent element spacing that is of the antenna of the sending device and that is determined by the processor, the element spacing of the antenna of the device, and the transmission distance D.
19. The device according to claim 18 , wherein the processor is further configured to determine an equivalent element spacing s g of the antenna of the sending device according to the transmission distance D and the element spacing of the antenna of the device, and s g meets the following formula:
s
g
s
2
=
(
p
+
1
max
(
N
t
,
N
r
)
)
D
λ
sin
θ
sin
ω
,
wherein
s 2 is the element spacing of the antenna of the device, D is the transmission distance D, P is a constant, λ is a wavelength, N t is a quantity of elements included in the antenna of the sending device, N r is a quantity of elements included in the antenna of the device, θ indicates an angle between the antenna of the sending device and a projection that is of the antenna of the sending device and that is on a reference plane, and ω indicates an angle between the antenna of the device and a projection that is of the antenna of the device and that is on the reference plane.
20. The device according to claim 17 , wherein the device further comprises:
a receiver, configured to: before the processor determines {tilde over (H)}, receive an indication message that is sent by the sending device and that is used to indicate the transmission distance D.