# US 8,570,885 B2 · Uplink feedback in a multimedia broadcast/multicast services (MBMS) wireless communications system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,570,885 B2 - Document ID: US8570885B2 - Status: Granted - Kind: B2 - Application number: 12/918,158 - Filed: 2009-02-18 - Published: 2010-12-23 - Granted: 2013-10-29 - Earliest claimed: 2008-02-19 - Assignees: NXP B.V. - Applicants: Qi Zhou; Dan Shang - Inventors: Qi Zhou; Dan Shang - Web page: https://patentgrep.com/patent/US8570885B2 ## CPC - H04L 1/0021: {in which the algorithm uses adaptive thresholds} - H04L 1/0026: {Transmission of channel quality indication} - H04L 1/0029: {Reduction of the amount of signalling, e.g. retention of useful signalling or differential signalling (power control H04W52/04)} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A technique for managing uplink feedback involves establishing a channel quality threshold range, for example, in terms of a channel quality indicator (CQI), broadcasting the channel quality threshold range to the mobile stations and using the channel quality threshold range to control the feedback of channel quality information. For example, the mobile stations determine their own mobile station-specific CQI and then generate CQI feedback information in response to a comparison between their own mobile station-specific CQI and the CQI threshold range. In an embodiment, if the CQI of a mobile station falls within the CQI threshold range, then the mobile station can transmit a reduced set of CQI feedback information. For example, the reduced set of CQI feedback information may be a single bit that indicates whether the mobile station-specific CQI is greater than or less than a CQI threshold or whether the CQI has crossed a CQI threshold. ## Claims ### Claim 1 A method for managing uplink feedback in a multimedia broadcast/multicast services (MBMS) wireless communications system that includes a base station and a plurality of mobile stations, the method comprising: establishing a common channel quality indicator (CQI) threshold range having an upper boundary and a lower boundary; transmitting the CQI threshold range to the plurality of mobile stations; at each mobile station: determining a mobile station-specific CQI; generating CQI feedback information in response to a comparison between the mobile station-specific CQI and the CQI threshold range; and transmitting the CQI feedback information to the base station. ### Claim 2 (depends on 1) The method of claim 1, further comprising, at the base station: updating the CQI threshold range in response to the CQI feedback information that is transmitted from the mobile stations. ### Claim 3 (depends on 2) The method of claim 2, wherein updating the CQI threshold range comprises changing at least one of a CQI threshold, the upper boundary of the CQI threshold range, and the lower boundary of the CQI threshold range. ### Claim 4 (depends on 1) The method of claim 1, wherein the CQI threshold range is defined in terms of a CQI threshold and wherein generating the CQI feedback information at the mobile stations comprises generating an indication of the magnitude of the mobile station-specific CQI relative to the CQI threshold. ### Claim 5 (depends on 1) The method of claim 1, wherein the CQI threshold range is defined in terms of a CQI threshold and wherein generating the CQI feedback information at the mobile stations comprises generating an indication that the mobile station-specific CQI has crossed the CQI threshold. ### Claim 6 (depends on 5) The method of claim 5, wherein the CQI information is transmitted in response to the CQI threshold being crossed. ### Claim 7 (depends on 1) The method of claim 1, wherein generating the CQI feedback information at the mobile stations comprises generating a full set of CQI feedback information when the magnitude of the mobile station-specific CQI is below the lower boundary of the CQI threshold range. ### Claim 8 (depends on 1) The method of claim 1, wherein generating the CQI feedback information at the mobile stations comprises generating a full set of CQI feedback information only when a mobile station-specific CQI falls within a specified range of the lower boundary of the CQI threshold range. ### Claim 9 (depends on 8) The method of claim 8, wherein a full set of CQI feedback information is generated in response to a probability factor that controls the number of mobile stations that generate a full set of CQI feedback information. ### Claim 10 (depends on 1) The method of claim 1, wherein generating the CQI feedback information at the mobile stations comprises generating a full set of CQI feedback information when the magnitude of the mobile station-specific CQI is above the upper boundary of the CQI threshold range and the mobile station has generated a negative acknowledgement (NACK). ### Claim 11 A system for managing uplink feedback in a multimedia broadcast/multicast services (MBMS) wireless communications system that includes a base station and a plurality of mobile stations, the system comprising: a channel quality module for establishing a channel quality indicator (CQI) threshold range having an upper boundary and a lower boundary; a transmitter for transmitting the CQI threshold range to the plurality of mobile stations; and wherein the channel quality module is further configured to update the CQI threshold range in response to CQI feedback information received from the mobile stations. ### Claim 12 (depends on 11) The system of claim 11, wherein updating the CQI threshold range comprises changing a CQI threshold. ### Claim 13 (depends on 11) The system of claim 11, wherein the CQI threshold range is defined in terms of a CQI threshold and wherein the CQI feedback information received from the mobile stations comprises an indication of the magnitude of mobile station-specific CQIs relative to the CQI threshold. ### Claim 14 (depends on 11) The system of claim 11, wherein the CQI threshold range is defined in terms of a CQI threshold and wherein the CQI feedback information received from the mobile stations comprises an indication that a mobile station-specific CQI has crossed the CQI threshold. ### Claim 15 A system for managing uplink feedback in a multimedia broadcast/multicast services (MBMS) wireless communications system that includes a base station and a plurality of mobile stations, the system comprising: a channel quality module for: generating a mobile station-specific channel quality indicator (CQI); generating CQI feedback information in response to a comparison between the mobile station-specific CQI and a CQI threshold range having an upper boundary and a lower boundary that is received from the base station; and a transmitter for transmitting the CQI feedback information to the base station. ### Claim 16 (depends on 15) The system of claim 15, wherein the CQI threshold range is defined in terms of a CQI threshold and wherein generating the CQI feedback information at the mobile stations comprises generating an indication of the magnitude of the mobile station-specific CQI relative to the CQI threshold. ### Claim 17 (depends on 15) The system of claim 15, wherein the CQI threshold range is defined in terms of a CQI threshold and wherein generating the CQI feedback information at the mobile stations comprises generating an indication that the mobile station-specific CQI has crossed the CQI threshold. ### Claim 18 (depends on 17) The system of claim 17, wherein the CQI information is transmitted from the mobile station in response to the CQI threshold being crossed. ### Claim 19 (depends on 15) The system of claim 15, wherein the channel quality module generates a full set of CQI feedback information when the magnitude of the mobile station-specific CQI is below the lower boundary of the CQI threshold range. ### Claim 20 (depends on 15) The system of claim 15, wherein the channel quality module generates a full set of CQI feedback information when the magnitude of the mobile station-specific CQI is above the upper boundary of the CQI threshold range and the mobile station has generated a negative acknowledgement (NACK).