Beam switching method and related device
Embodiments provide a beam switching method and a related device. Under the method a first subframe sent by a base station by using a first beam can be received by a terminal device. The first subframe includes first-order downlink control information and second-order downlink control information. The terminal device can search for the second-order downlink control information based on the first-order downlink control information. The first-order downlink control information includes location indication information of the second-order downlink control information in the first subframe. the terminal device can switch from the first beam to a second beam based on the found second-order downlink control information to receive a second subframe. The downlink control information includes a switching indication field of the second beam. In this way, flexibility of beam switching is improved, load balancing of a control channel is implemented, and a latency of beam switching is reduced.
1. A beam switching method, wherein the method comprises:
receiving, by a terminal device, a first subframe and a second subframe sent by a base station; and
switching, by the terminal device, from a first narrow beam within coverage of a first wide beam to a second narrow beam within coverage of a second wide beam based on access control information in the first subframe and downlink control information in the second subframe to receive a third subframe, wherein the access control information comprises switching configuration information of the second wide beam, and the downlink control information comprises a switching indication field of the second narrow beam.
2. The method according to claim 1 , wherein both the first subframe and the second subframe comprise first-order downlink control information and second-order downlink control information; and, wherein
switching, by the terminal device, from a first narrow beam within coverage of a first wide beam to a second narrow beam within coverage of a second wide beam based on access control information in the first subframe and downlink control information in the second subframe to receive a third subframe comprises:
searching, by the terminal device based on the first-order downlink control information in the first subframe, for the access control information in a data channel as indicated by the second-order downlink control information in the first subframe, and searching for the second-order downlink control information in the second subframe based on the first-order downlink control information in the second subframe, wherein the first-order downlink control information in the first subframe comprises location indication information of the second-order downlink control information in the first subframe, and the first-order downlink control information in the second subframe comprises location indication information of the second-order downlink control information in the second subframe; and
switching, by the terminal device, from the first narrow beam within the coverage of the first wide beam to the second narrow beam within the coverage of the second wide beam based on the found access control information in the data channel as indicated by the second-order downlink control information in the first subframe, and based on the second-order downlink control information in the second subframe.
3. The method according to claim 2 , wherein switching, by the terminal device, from the first narrow beam within the coverage of the first wide beam to the second narrow beam within the coverage of the second wide beam based on the found access control information that is in the data channel and that is indicated by the second-order downlink control information in the first subframe, and the found second-order downlink control information in the second subframe comprises:
searching, by the terminal device, for the second narrow beam within the coverage of the second wide beam from a preset beam mapping table based on the switching configuration information and the location indication information, wherein the beam mapping table is sent by the base station.
4. The method according to claim 1 , wherein the switching indication field comprises a beam number, wherein the beam number indicates a quantity of bits of a first preset length, the access control information comprises a beam group number, and the beam group number is a quantity of bits of a second preset length.
5. The method according to claim 1 , wherein a time interval between the first subframe and the third subframe is M subframes, a time interval between the second subframe and the third subframe is N subframes, and M and N are integers greater than or equal to 0.
6. The method according to claim 5 , wherein N is a dynamically changing value, and wherein
downlink control information in the first subframe comprises indication information of M; and/or
downlink control information in the third subframe comprises indication information of N.