Beam tracking method, apparatus, and system

Abstract

The present invention relates to the field of communications technologies, and discloses a beam tracking method, apparatus, and system, so as to ensure rapid discovery and to switch from an optimal link to a backup link in time, or switch from a backup link to an optimal link, thereby effectively improving a throughput of a system link. The beam tracking method includes: transmitting, by a beam tracking initiator, a beam tracking request to a beam tracking responder; receiving, by the beam tracking initiator, an enhanced beam tracking training auxiliary sequence transmitted, according to the enhanced beam tracking request, by the beam tracking responder; and when it is determined according to a reception detection result of the enhanced beam tracking training auxiliary sequence that it is necessary to switch to a backup beam link, transmitting, by the beam tracking initiator, first link switching information to the beam tracking responder.

What is claimed is: 
     
         1 . A beam tracking method, comprising:
 transmitting, by a beam tracking initiator, a beam tracking request to a beam tracking responder;   receiving, by the beam tracking initiator, an enhanced beam tracking training auxiliary sequence transmitted, according to the enhanced beam tracking request, by the beam tracking responder, wherein the enhanced beam tracking training auxiliary sequence comprises: a beam tracking training auxiliary sequence unit of a current beam link, a beam tracking training auxiliary sequence unit of a proximate selectable beam link of the current beam link, and a beam tracking training auxiliary sequence unit of a first backup beam link; and   when it is determined according to a reception detection result of the enhanced beam tracking training auxiliary sequence that it is necessary to switch to a backup beam link, transmitting, by the beam tracking initiator, first link switching information to the beam tracking responder, wherein the first link switching information is used to instruct the beam tracking initiator and the beam tracking responder to switch to a second backup beam link.   
     
     
         2 . The method according to  claim 1 , wherein the transmitting, by a beam tracking initiator, a beam tracking request to a beam tracking responder comprises:
 if the current beam link via which the beam tracking initiator and the beam tracking responder perform communication is an optimal link after beamforming, and the beam tracking initiator detects that signal attenuation of the current beam link exceeds a preset threshold, transmitting, by the beam tracking initiator, the beam tracking request to the beam tracking responder; or,   if the current beam link via which the beam tracking initiator and the beam tracking responder perform communication is a second optimal link after beamforming, and the beam tracking initiator detects that an optimal link after beamforming is recovered, transmitting, by the beam tracking initiator, the beam tracking request to the beam tracking responder.   
     
     
         3 . The method according to  claim 1 , wherein
 the beam tracking training auxiliary sequence unit of the current beam link comprises: an automatic gain control AGC field and a training sequence TRN field of the current beam link;   the beam tracking training auxiliary sequence unit of the proximate selectable beam link of the current beam link comprises: an AGC field and a TRN field of the proximate selectable beam link of the current beam link; and   the beam tracking training auxiliary sequence unit of the first backup beam link comprises: a short training sequence STF field and a channel estimation CE field of the first backup beam link.   
     
     
         4 . The method according to  claim 1 , wherein the receiving, by the beam tracking initiator, an enhanced beam tracking training auxiliary sequence transmitted, according to the enhanced beam tracking request, by the beam tracking responder comprises:
 receiving, by the beam tracking initiator, the beam tracking training auxiliary sequence unit, of the current beam link, transmitted by using the current beam link by the beam tracking responder, receiving the beam tracking training auxiliary sequence unit, of the proximate selectable beam link of the current beam link, transmitted by using the proximate selectable beam link of the current beam link by the beam tracking responder, and receiving the beam tracking training auxiliary sequence unit, of the first backup beam link, transmitted by using the first backup beam link by the beam tracking responder.   
     
     
         5 . The method according to  claim 1 , wherein before the transmitting, by a beam tracking initiator, a beam tracking request to a beam tracking responder, the method further comprises:
 transmitting, by the beam tracking initiator, enhanced beam tracking information to the beam tracking responder, wherein the enhanced beam tracking information comprises: antenna configuration information of the first backup beam link and an identity of requesting the beam tracking responder to transmit the enhanced beam tracking training auxiliary sequence; and   receiving, by the beam tracking initiator, response information transmitted by the beam tracking responder, wherein the response information is used to instruct the beam tracking responder whether to transmit the enhanced beam tracking training auxiliary sequence.   
     
     
         6 . The method according to  claim 5 , wherein the transmitting, by the beam tracking initiator, enhanced beam tracking information to the beam tracking responder comprises:
 transmitting, by the beam tracking initiator, the enhanced beam tracking information to the beam tracking responder in a sector-level sweep SLS phase; or,   transmitting, by the beam tracking initiator, the enhanced beam tracking information to the beam tracking responder in a beam refinement protocol BRP phase.   
     
     
         7 . The method according to  claim 5 , wherein the enhanced beam tracking information is in an enhanced beam tracking information unit of a media access control MAC layer;
 the transmitting, by the beam tracking initiator, enhanced beam tracking information to the beam tracking responder comprises:   transmitting, by the beam tracking initiator to the beam tracking responder, a sector sweep SSW frame or a sector sweep feedback SSW-feedback frame comprising, in the SLS phase, the enhanced beam tracking information unit; or,   transmitting, by the beam tracking initiator to the beam tracking responder, a beam refinement protocol BRP frame comprising, in the BRP phase, the enhanced beam tracking information unit; and   the receiving, by the beam tracking initiator, response information transmitted by the beam tracking responder comprises:   receiving, by the beam tracking initiator, an SSW frame or an SSW-feedback frame, carrying an enhanced beam tracking information unit of the response information, transmitted by the beam tracking responder; or,   receiving, by the beam tracking initiator, a BRP frame, carrying an enhanced beam tracking information unit of the response information, transmitted by the beam tracking responder.   
     
     
         8 . The method according to  claim 7 , wherein the enhanced beam tracking information unit comprises:
 an information element identity Element ID, used to represent an ID of a current information unit;   a length Length, used to represent a length of the current information unit;   a backup beam link antenna weight vector setting Backup AWV Setting, used to represent whether to update an antenna vector setting of a peer backup beam link;   a peer transmit-sector identity Peer Tx_Sector ID, used to represent whether a peer transmit-sector identity needs to be backed up;   a peer transmit-antenna identity Peer Tx_Antenna ID, used to represent whether a peer transmit-antenna identity needs to be backed up;   an enhanced beam tracking in receiver request E-BT-R Request, used to represent whether to request a peer to receive a training auxiliary sequence according to an enhanced beam tracking mode;   an enhanced beam tracking in receiver OK E-BR-R OK, used to represent whether itself receives a training auxiliary sequence of an enhanced beam tracking mode;   an enhanced beam tracking in transmitter request E-BT-T Request, used to represent whether to request a peer to transmit a training auxiliary sequence according to an enhanced beam tracking mode; and   an enhanced beam tracking in transmitter OK E-BR-T OK, used to represent whether itself transmits a training auxiliary sequence of an enhanced beam tracking mode.   
     
     
         9 . The method according to  claim 8 , wherein the transmitting, by the beam tracking initiator, first link switching information to the beam tracking responder comprises:
 transmitting, by the beam tracking initiator to the beam tracking responder, the first link switching information carried in a frame header of a physical layer frame.   
     
     
         10 . The method according to  claim 8 , wherein the enhanced beam tracking information unit further comprises:
 a switch to backup beam link identity Switch to Backup AWV, used to represent whether to switch to a backup beam link in a next frame and use an antenna configuration of the current beam link as an antenna configuration of the backup beam link in the next frame; and   the transmitting, by the beam tracking initiator, first link switching information to the beam tracking responder comprises:   transmitting, by the beam tracking initiator to the beam tracking responder, an SSW frame or an SSW-feedback carrying an enhanced beam tracking information unit of the first link switching information; or,   transmitting, by the beam tracking initiator to the beam tracking responder, a BRP frame carrying an enhanced beam tracking information unit of the first link switching information.   
     
     
         11 . The method according to  claim 4 , wherein after the receiving, by the beam tracking initiator, an enhanced beam tracking training auxiliary sequence transmitted, according to the enhanced beam tracking request, by the beam tracking responder, and before the transmitting, by the beam tracking initiator, first link switching information to the beam tracking responder, the method further comprises: if the current beam link via which the beam tracking initiator and the beam tracking responder perform communication is an optimal link after beamforming or a proximate selectable beam link of the optimal link,
 determining whether it is necessary to switch to a backup beam link in a next frame; and   in a case in which it is necessary to switch to a backup beam link, calculating an azimuth of the second backup beam link that needs to be switched to in the next frame, and an azimuth of a backup beam link when the second backup beam link is used as a current link.   
     
     
         12 . A beam tracking device, comprising:
 a transmitter, configured to transmit a beam tracking request to a beam tracking responder; and   a receiver, configured to receive an enhanced beam tracking training auxiliary sequence transmitted, according to the enhanced beam tracking request, by the beam tracking responder, wherein the enhanced beam tracking training auxiliary sequence comprises: a beam tracking training auxiliary sequence unit of a current beam link, a beam tracking training auxiliary sequence unit of a proximate selectable beam link of the current beam link, and a beam tracking training auxiliary sequence unit of a first backup beam link,   a processor, configured to determine it is necessary to switch to a backup beam link according to a reception detection result of the enhanced beam tracking training auxiliary sequence,   the transmitter is further configured to that transmit first link switching information to the beam tracking responder, wherein the first link switching information is used to instruct the beam tracking initiator and a beam tracking responder to switch to a second backup beam link.   
     
     
         13 . The device according to  claim 12 , wherein the transmitter is specifically configured to:
 if the current beam link via which the beam tracking initiator and the beam tracking responder perform communication is an optimal link after beamforming, and the beam tracking initiator detects that signal attenuation of the current beam link exceeds a preset threshold, transmit the beam tracking request to the beam tracking responder; or,   if the current beam link via which the beam tracking initiator and the beam tracking responder perform communication is a second optimal link after beamforming, and the beam tracking initiator detects that an optimal link after beamforming is recovered, transmit the beam tracking request to the beam tracking responder.   
     
     
         14 . The device according to  claim 12 , wherein the receiver is specifically configured to receive the beam tracking training auxiliary sequence unit, of the current beam link, transmitted by using the current beam link by the beam tracking responder, the beam tracking training auxiliary sequence unit, of the proximate selectable beam link of the current beam link, transmitted by using the proximate selectable beam link of the current beam link, and the beam tracking training auxiliary sequence unit, of the first backup beam link, transmitted by using the first backup beam link. 
     
     
         15 . The device according to  claim 12 , wherein the transmitter is further configured to: before the beam tracking request is transmitted to the beam tracking responder, transmit enhanced beam tracking information to the beam tracking responder, wherein the enhanced beam tracking information comprises: information of the first backup beam link and an identity of requesting the beam tracking responder to transmit the enhanced beam tracking training auxiliary sequence; and
 the receiver is further configured to receive response information transmitted by the beam tracking responder, wherein the response information is used to instruct the beam tracking responder whether to transmit the enhanced beam tracking training auxiliary sequence.   
     
     
         16 . The device according to  claim 12 ,
 if the current beam link via which the beam tracking initiator and the beam tracking responder perform communication is an optimal link after beamforming or a proximate selectable beam link of the optimal link,   the processor is further configured to determine whether it is necessary to switch to a backup beam link in a next frame; and   the processor is further configured to: in a case in which the processor determines that it is necessary to switch to a backup beam link, calculate an azimuth of the second backup beam link that needs to be switched to in the next frame, and an azimuth of a backup beam link when the second backup beam link is used as a current link.   
     
     
         17 . A beam tracking device, comprising:
 a receiver, configured to receive a beam tracking request transmitted by a beam tracking initiator; and   a transmitter, configured to transmit an enhanced beam tracking training auxiliary sequence to the beam tracking initiator according to the received beam tracking request, wherein the enhanced beam tracking training auxiliary sequence comprises: a beam tracking training auxiliary sequence unit of a current beam link, a beam tracking training auxiliary sequence unit of a proximate selectable beam link of the current beam link, and a beam tracking training auxiliary sequence unit of a first backup beam link, wherein   the receiver is further configured to receive first link switching information transmitted by the beam tracking initiator, wherein the first link switching information is used to instruct the beam tracking initiator and a beam tracking responder to switch to a second backup beam link.   
     
     
         18 . The device according to  claim 17 , wherein the receiver is specifically configured to:
 if the current beam link via which the beam tracking initiator and the beam tracking responder perform communication is an optimal link after beamforming, and the beam tracking initiator detects that signal attenuation of the current beam link exceeds a preset threshold, receive the beam tracking request transmitted by the beam tracking initiator; or,   if the current beam link via which the beam tracking initiator and the beam tracking responder perform communication is a second optimal link after beamforming, and the beam tracking initiator detects that an optimal link after beamforming is recovered, receive the beam tracking request transmitted by the beam tracking initiator.   
     
     
         19 . The device according to  claim 17 , wherein the transmitter is specifically configured to transmit the beam tracking training auxiliary sequence unit of the current beam link to the beam tracking initiator by using the current beam link, transmit the beam tracking training auxiliary sequence unit of the proximate selectable beam link of the current beam link to the beam tracking initiator by using the proximate selectable beam link of the current beam link, and transmit the beam tracking training auxiliary sequence unit of the first backup beam link to the beam tracking initiator by using the first backup beam link. 
     
     
         20 . The device according to  claim 17 , wherein the receiver is further configured to: before the beam tracking request transmitted by the beam tracking initiator is received, receive enhanced beam tracking information transmitted by the beam tracking initiator, wherein the enhanced beam tracking information comprises: information of the first backup beam link and an identity of requesting the beam tracking responder to transmit the enhanced beam tracking training auxiliary sequence; and
 the transmitter is further configured to transmit response information to the beam tracking initiator according to the received enhanced beam tracking information, wherein the response information is used to instruct the beam tracking responder whether to transmit the enhanced beam tracking training auxiliary sequence.