Beam alignment method and apparatus
A network device receives a first uplink signal from a terminal device; the network device calculates a conjugate phase corresponding to the first uplink signal, and determines, based on the conjugate phase, a narrow beam whose direction of arrival is opposite to a direction of arrival of the first uplink signal as a target transmit beam aligned between the network device and the terminal device; and the network device communicates with the terminal device by using the target transmit beam.
1 . A method, comprising:
receiving, by a terminal device, a first downlink signal from a network device;
calculating, by a conjugate phase processing circuit of the terminal device, a conjugate phase of the first downlink signal, the conjugate phase processing circuit implemented in an analog domain;
determining, by the terminal device based on the conjugate phase, a narrow beam having a direction of arrival that is opposite to a direction of arrival of the first downlink signal to be a target uplink transmit beam of the terminal device; and
communicating, by the terminal device, with the network device using the target uplink transmit beam.
2 . The method according to claim 1 , further comprising:
receiving, by the terminal device, a second downlink signal from the network device, wherein the second downlink signal comprises a measurement result of a target receive beam of the network device or an identifier of the target receive beam of the network device; and
determining, by the terminal device based on the second downlink signal, a target uplink receive beam aligned with the target uplink transmit beam.
3 . The method according to claim 1 , further comprising:
before the receiving, by the terminal device, the first downlink signal from the network device, transmitting, by the terminal device, a radio signal to the network device using fixed wide beams pointing to different directions, wherein a set of directions of the fixed wide beams pointing to different directions covers a signal coverage area of the network device.
4 . The method according to claim 1 , wherein the calculating the conjugate phase comprises:
calculating, by the conjugate phase processing circuit of the terminal device based on the direction of arrival of the first downlink signal, a conjugate phase corresponding to a reference signal.
5 . The method according to claim 4 , wherein the conjugate phase processing circuit is coupled to one or more antennas of the terminal device.
6 . The method according to claim 5 , wherein the conjugate phase processing circuit comprises a signal modulation circuit, a conjugate phase extraction circuit, a phase conjugate calculation circuit, and a reverse array system that are implemented in the analog domain.
7 . The method according to claim 1 , further comprising:
after the communicating, by the terminal device, with the network device using the target uplink transmit beam, calculating, by the terminal device based on a third downlink signal from the network device, a conjugate phase corresponding to the third downlink signal; and
adjusting, by the terminal device based on the conjugate phase corresponding to the third downlink signal, the target uplink transmit beam to a narrow beam having a direction of arrival that is opposite to a direction of arrival of the third downlink signal.
8 . An apparatus, comprising:
a transceiver, configured to receive a first downlink signal from a network device;
a conjugate phase processing circuit implemented in an analog domain;
at least one processor; and
a non-transitory computer readable storage medium storing a program that is executable by at least one processor, the program including instructions to cause the apparatus to perform:
calculating a conjugate phase of the first downlink signal, and
determining, by the conjugate phase processing circuit based on the conjugate phase, a narrow beam having a direction of arrival that is opposite to a direction of arrival of the first downlink signal to be a target uplink transmit beam of the apparatus, and
wherein the transceiver is further configured to communicate with the network device using the target uplink transmit beam.
9 . The apparatus according to claim 8 , wherein the transceiver is further configured to receive a second downlink signal from the network device, wherein the second downlink signal comprises a measurement result of a target receive beam of the network device or an identifier of the target receive beam of the network device; and
wherein the program further includes instructions to cause the apparatus to perform:
determining, based on the second downlink signal, a target uplink receive beam aligned with the target uplink transmit beam.
10 . The apparatus according to claim 8 , wherein the transceiver is further configured to:
before receiving the first downlink signal, transmit a radio signal to the network device using fixed wide beams pointing to different directions, wherein a set of directions of the fixed wide beams pointing to different directions covers a signal coverage area of the network device.
11 . The apparatus according to claim 8 , wherein the calculating the conjugate phase comprises:
using the conjugate phase processing circuit to calculate, based on the direction of arrival of the first downlink signal, the conjugate phase corresponding to a reference signal.
12 . The apparatus according to claim 11 , wherein the conjugate phase processing circuit is coupled to one or more antennas of the apparatus.
13 . The apparatus according to claim 12 , wherein the conjugate phase processing circuit comprises a signal modulation circuit, a conjugate phase extraction circuit, a phase conjugate calculation circuit, and a reverse array system that are implemented in the analog domain.
14 . The apparatus according to claim 8 , wherein the transceiver is further configured to: after communicating with the network device by using the target uplink transmit beam, receive a third downlink signal from the network device; and
wherein the program further includes instructions to cause the apparatus to perform:
calculating a conjugate phase corresponding to the third downlink signal; and
adjusting, based on the conjugate phase corresponding to the third downlink signal, the target uplink transmit beam to a narrow beam whose direction of arrival is opposite to a direction of arrival of the third downlink signal.
15 . A non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores instructions, and when the instructions are executed by one or more processors, an apparatus is caused to perform:
receiving a first downlink signal from a network device;
calculating, by a conjugate phase processing circuit of the apparatus, a conjugate phase of the first downlink signal, the conjugate phase processing circuit implemented in an analog domain;
determining, based on the conjugate phase, a narrow beam having a direction of arrival that is opposite to a direction of arrival of the first downlink signal to be a target uplink transmit beam of the apparatus; and
communicating with the network device using the target uplink transmit beam.
16 . The non-transitory computer-readable storage medium according to claim 15 , wherein when the instructions are executed by the one or more processors, the apparatus is further caused to perform:
receiving a second downlink signal from the network device, wherein the second downlink signal comprises a measurement result of a target receive beam of the network device or an identifier of the target receive beam of the network device; and
determining, based on the second downlink signal, a target uplink receive beam aligned with the target uplink transmit beam.
17 . The non-transitory computer-readable storage medium according to claim 15 , wherein when the instructions are executed by the one or more processors, the apparatus is further caused to perform:
before the receiving the first downlink signal, transmitting a radio signal to the network device using fixed wide beams pointing to different directions, wherein a set of directions of the fixed wide beams pointing to different directions covers a signal coverage area of the network device.
18 . The non-transitory computer-readable storage medium according to claim 15 , wherein when the instructions are executed by the one or more processors, the apparatus is further caused to perform:
calculating, based on the direction of arrival of the first downlink signal, a conjugate phase corresponding to a reference signal.
19 . The non-transitory computer-readable storage medium according to claim 18 , wherein the reference signal is a channel state information reference signal (CSI-RS), a synchronization signal broadcast channel block (SS/PBCH block), a demodulation reference signal (DMRS), a phase tracking reference signal (PTRS), or a tracking reference signal (TRS).
20 . The non-transitory computer-readable storage medium according to claim 15 , wherein when the instructions are executed by the one or more processors, the apparatus is further caused to perform:
after the communicating with the network device by using the target uplink transmit beam, receiving a third downlink signal from the network device;
calculating a conjugate phase corresponding to the third downlink signal; and
adjusting, based on the conjugate phase corresponding to the third downlink signal, the target uplink transmit beam to a narrow beam whose direction of arrival is opposite to a direction of arrival of the third downlink signal.