A communications device in a high-frequency system, comprising: a scan module, configured to use a single beam for each space S region in a to-be-scanned sector of a cell to poll or cover all time T regions in the S region in a time-division manner, and send a synchronization sequence to user equipment, in the T region by using a preset frame structure, wherein the frame structure is carried in a beam signal; and a determining module, configured to receive a sequence that is fed back by the user equipment, determine a location of the user equipment according to the sequence, and determine, according to the location of the user equipment, a serving beam for a base station to communicate with the user equipment, to confirm that scanning for the user equipment is completed; wherein the scan module is specifically configured to: insert N OFDM symbols into one downlink timeslot in one radio subframe in the frame structure, insert the synchronization sequence into the N OFDM symbols, and send the synchronization sequence to the user equipment in the T region by using the N OFDM symbols, wherein N is equal to a quantity of T regions in the S region; and wherein the synchronization sequence comprises a sequence ID of the beam that is emitted by the base station to scan the T region; and the ID of the beam comprises a cell sequence C_ID, a sector sequence SEC_ID, a space sequence S_ID, and a time sequence T_ID. a scan module, configured to use a single beam for each space S region in a to-be-scanned sector of a cell to poll or cover all time T regions in the S region in a time-division manner, and send a synchronization sequence to user equipment, in the T region by using a preset frame structure, wherein the frame structure is carried in a beam signal; and a determining module, configured to receive a sequence that is fed back by the user equipment, determine a location of the user equipment according to the sequence, and determine, according to the location of the user equipment, a serving beam for a base station to communicate with the user equipment, to confirm that scanning for the user equipment is completed; wherein the scan module is specifically configured to: insert N OFDM symbols into one downlink timeslot in one radio subframe in the frame structure, insert the synchronization sequence into the N OFDM symbols, and send the synchronization sequence to the user equipment in the T region by using the N OFDM symbols, wherein N is equal to a quantity of T regions in the S region; and wherein the synchronization sequence comprises a sequence ID of the beam that is emitted by the base station to scan the T region; and the ID of the beam comprises a cell sequence C_ID, a sector sequence SEC_ID, a space sequence S_ID, and a time sequence T_ID. insert N OFDM symbols into one downlink timeslot in one radio subframe in the frame structure, insert the synchronization sequence into the N OFDM symbols, and send the synchronization sequence to the user equipment in the T region by using the N OFDM symbols, wherein N is equal to a quantity of T regions in the S region; and wherein the synchronization sequence comprises a sequence ID of the beam that is emitted by the base station to scan the T region; and the ID of the beam comprises a cell sequence C_ID, a sector sequence SEC_ID, a space sequence S_ID, and a time sequence T_ID.