# US 9,439,174 B2 · Method and apparatus for transmitting beam information in wireless communication system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,439,174 B2 - Document ID: US9439174B2 - Status: Granted - Kind: B2 - Application number: 13/850,693 - Filed: 2013-03-26 - Published: 2013-10-03 - Granted: 2016-09-06 - Earliest claimed: 2012-03-27 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co. Ltd. - Inventors: Hyun-Kyu Yu; Tae-Young Kim; Su-Ryong Jeong - Web page: https://patentgrep.com/patent/US9439174B2 ## CPC - H04W 72/20: Control channels or signalling for resource management - H04B 7/0632: {Channel quality parameters, e.g. channel quality indicator [CQI]} - H04B 7/0639: {Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection} - H04B 7/06952: {Selecting one or more beams from a plurality of beams, e.g. beam training, management or sweeping} - H04L 1/188: {Time-out mechanisms} - H04W 16/28: using beam steering - H04W 74/08: Non-scheduled access, e.g. ALOHA (hybrid access H04W74/02) - H04W 28/06: Optimizing {the usage of the radio link}, e.g. header compression, information sizing {, discarding information (system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365)} - H04W 48/12: using downlink control channel - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A method and a mobile station of transmitting beam information by a mobile station in a wireless communication system are provided. The mobile station determines whether a particular a particular event according to communication with a base station has occurred, and transmits information on at least one DownLink (DL) transmission beam among N number of DL transmission beams to the base station using a contention-based feedback channel according to a result of the determination. ## Claims ### Claim 1 A method for transmitting beam information by a mobile station in a wireless communication system, the method comprising: transmitting uplink reference signals through a plurality of uplink transmission beams of the mobile station; determining whether uplink feedback information for at least one uplink transmission beam among the plurality of uplink transmission beams is received from a base station within a preset time period; receiving, if the uplink feedback information is not received from the base station within the preset time period, downlink reference signals transmitted through a plurality of downlink transmission beams of the base station; and transmitting downlink feedback information generated based on receive strengths of the downlink reference signals. ### Claim 2 (depends on 1) The method of claim 1, wherein the transmitting of the downlink feedback information comprises: measuring the received strengths of the downlink reference signals; determining whether at least one received strength among the measured received strengths is greater than a threshold; and transmitting, if at least one receive strength among the measured received strengths is greater than a threshold, the downlink feedback information comprising information related to at least one downlink transmission beam corresponding to the at least one received strength. ### Claim 3 (depends on 2) The method of claim 2, wherein, if the at least one receive strength among the measured received strengths is less than or equal to a threshold, trying to access an adjacent base station. ### Claim 4 (depends on 1) The method of claim 1, wherein the transmitting of the downlink feedback information comprises: receiving a transmission request of the downlink feedback information from the base station. ### Claim 5 (depends on 1) The method of claim 1, wherein the preset time period is set as a maximum value of the time period from a transmission time point of the uplink reference signals to a reception time point of the uplink feedback information. ### Claim 6 (depends on 1) The method of claim 1, wherein, if the uplink feedback information is received from the base station, determining that the uplink feedback information indicates a cell change of the mobile terminal; and trying, if the uplink feedback information indicates the cell change of the mobile terminal, to access an adjacent base station. ### Claim 7 A method for receiving beam information by a base station in a wireless communication system, the method comprising: transmitting uplink feedback information generated based on receive strengths of uplink reference signals transmitted through a plurality of uplink transmission beams of a mobile station; transmitting downlink reference signals through a plurality of downlink transmission beams of the base station; determining whether downlink feedback information for at least one downlink transmission beam among the plurality of downlink transmission beams is received from the mobile terminal within a preset time period; and determining, if the downlink feedback information is received from the mobile station, a downlink transmission beam to be used for downlink signal transmission to the mobile station among the plurality of downlink transmission beams based on the downlink feedback information. ### Claim 8 (depends on 7) The method of claim 7, wherein the transmitting of the uplink feedback information comprises: determining whether at least one receive strength among the receive strengths of the uplink reference signals is greater than a threshold; and generating, if the at least one receive strength is greater than the threshold, the uplink feedback information comprising information related to at least one uplink transmission beam corresponding to the at least one received strength. ### Claim 9 (depends on 8) The method of claim 8, wherein, if at least one receive strength is not greater than a threshold, transmitting a retransmission request for the uplink reference signals to the mobile station. ### Claim 10 (depends on 7) The method of claim 7, wherein the transmitting of the downlink reference signals comprises: transmitting, if an ACK signal for receiving of the uplink feedback information is received from the mobile terminal, a transmission request of the downlink feedback information to the mobile terminal. ### Claim 11 (depends on 7) The method of claim 7, wherein, if at least one receive strength among the receive strengths of the uplink reference signals is not greater than a threshold, transmitting a signal indicating cell change of the mobile station to the mobile station. ### Claim 12 A mobile station for transmitting beam information in a wireless communication system, the mobile station comprising: a transceiver configured to: transmit uplink reference signals through a plurality of uplink transmission beams of the mobile station, and transmit downlink feedback information generated based on receive strengths of downlink reference signals; a controller configured to determine whether uplink feedback information for at least one uplink transmission beam among the plurality of uplink transmission beams is received from a base station within a preset time period; and if the uplink feedback information is not received from the base station within the preset time period, the transceiver is further configured to receive the downlink reference signals transmitted through a plurality of downlink transmission beams of the base station. ### Claim 13 (depends on 12) The mobile station of claim 12, wherein the controller is further configured to: measure the received strengths of the downlink reference signals, determine whether at least one received strength among the measured received strengths is greater than a threshold, and control, if at least one receive strength among the measured received strengths is greater than a threshold, the transceiver configured to transmit the downlink feedback information comprising information related to at least one downlink transmission beam corresponding to the at least one received strength. ### Claim 14 (depends on 12) The mobile station of claim 12, wherein, if the at least one receive strength among the measured received strengths is less than or equal to a threshold, the controller is further configured to try to access an adjacent base station. ### Claim 15 (depends on 12) The mobile station of claim 12, wherein the transceiver is further configured to receive a transmission request of the downlink feedback information from the base station. ### Claim 16 (depends on 12) The mobile station of claim 12, wherein the preset time period is set as a maximum value of the time period from a transmission time point of the uplink reference signals to a reception time point of the uplink feedback information. ### Claim 17 (depends on 12) The mobile station of claim 12, wherein the controller is further configured to: determine that the uplink feedback information indicates a cell change of the mobile terminal if the uplink feedback information is received from the base station, and try to access an adjacent base station if the uplink feedback information indicates the cell change of the mobile terminal. ### Claim 18 A base station for receiving beam information in a wireless communication system, the base station comprising: a transceiver configured to: transmit uplink feedback information generated based on receive strengths of uplink reference signals transmitted through a plurality of uplink transmission beams of a mobile station, and transmit downlink reference signals through a plurality of downlink transmission beams of the base station; and a controller configured to: determine whether downlink feedback information for at least one downlink transmission beam among the plurality of downlink transmission beams is received from the mobile terminal within a preset time period, and determine, if the downlink feedback information is received from the mobile station, a downlink transmission beam to be used for downlink signal transmission to the mobile station among the plurality of downlink transmission beams based on the downlink feedback information. ### Claim 19 (depends on 18) The base station of claim 18, wherein the controller is further configured to: determine whether at least one receive strength among the receive strengths of the uplink reference signals is greater than a threshold, and generate the uplink feedback information comprising information related to at least one uplink transmission beam corresponding to the at least one received strength if the at least one receive strength is greater than the threshold. ### Claim 20 (depends on 18) The base station of claim 18, wherein, if at least one receive strength is not greater than a threshold, the transceiver is further configured to transmit a retransmission request for the uplink reference signals to the mobile station. ### Claim 21 (depends on 18) The base station of claim 18, wherein, if an ACK signal for receiving of the uplink feedback information is received from the mobile terminal, the transceiver is further configured to transmit a transmission request of the downlink feedback information to the mobile terminal. ### Claim 22 (depends on 18) The base station of claim 18, wherein, if at least one receive strength among the receive strengths of the uplink reference signals is not greater than a threshold, the transceiver is further configured to transmit a signal indicating cell change of the mobile station to the mobile station.