# US 8,787,189 B2 · Feedback method and system of channel quality indicatior > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,787,189 B2 - Document ID: US8787189B2 - Status: Granted - Kind: B2 - Application number: 13/257,790 - Filed: 2009-12-28 - Published: 2012-03-01 - Granted: 2014-07-22 - Earliest claimed: 2009-03-20 - Assignees: Zte Corporation - Applicants: Yunfeng Sun; Jing Jiang; Changqing Zhu; Junfeng Zhang - Inventors: Yunfeng Sun; Jing Jiang; Changqing Zhu; Junfeng Zhang - Web page: https://patentgrep.com/patent/US8787189B2 ## CPC - H04L 41/5032: {Generating service level reports} - H04B 7/024: Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems - H04B 7/0632: {Channel quality parameters, e.g. channel quality indicator [CQI]} - H04B 7/0641: {Differential feedback} - H04B 7/065: {Variable contents, e.g. long-term or short-short} - H04W 24/10: Scheduling measurement reports {; Arrangements for measurement reports} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04B: TRANSMISSION - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A method of CQI feedback comprises: in a CoMP system, a terminal feeding back a CQI corresponding to a comprehensive channel formed between the terminal and all transmission nodes in a CATS or each CQI corresponding to each channel between the terminal and each transmission node. A system of CQI feedback; in the system is also disclosed, a feedback unit at the terminal side is used in the CoMP system to calculate and feed back the CQI corresponding to the comprehensive channel formed between the terminal and all the transmission nodes in the CATS or each CQI corresponding to each channel between the terminal and each transmission node. With the method and system of the present invention, not only the CQI feedback in the CoMP system can be realized, but also the difference between the CQI feedback in the control channel and that in the traffic channel can be avoided. ## Claims ### Claim 1 A method of channel quality indicator feedback, comprising: in a multi-point coordinated transmission and reception (CoMP) system, a terminal feeding back a channel quality indicator corresponding to a comprehensive channel formed between the terminal and all transmission nodes in a CoMP active transmission point set, or each channel quality indicator corresponding to each channel between each transmission node and the terminal; further comprising: in the CoMP active transmission point set, different transmission nodes applying the same modulation and encoding method. ### Claim 2 (depends on 1) The method of claim 1, wherein, the type of the transmission node comprises a primary node; and said feedback further comprises: the terminal feeding back a channel quality indicator corresponding to a channel between the primary node and the terminal to the primary node; and the terminal feeding back the channel quality indicator corresponding to the comprehensive channel to the primary node, or the terminal feeding back to the primary node each channel quality indicator of each channel between the terminal and each non-primary node except the primary node in the CoMP active transmission point set. ### Claim 3 (depends on 2) The method of claim 2, wherein, the level of each channel quality indicator is different from or the same as the level of the channel quality indicator corresponding to the comprehensive channel. ### Claim 4 (depends on 3) The method of claim 3, wherein, the feedback further comprises: the terminal feeding back according to different feedback methods; wherein, the feedback methods comprise: full bandwidth feedback, feedback of high level configuring sub-bands or feedback of the terminal selecting sub-bands; and after the feedback, the method further comprises a determining process of modulation and encoding, and the determining process of the modulation and encoding comprises: corresponding to the different feedback methods, the primary node performing resource scheduling according to the channel quality indicator based on the full bandwidth or different sub-band and fed back by the terminal, and selecting a matching modulation and encoding method to modulate and encode data of scheduled users. ### Claim 5 (depends on 4) The method of claim 4, wherein, when the feedback method is the feedback of the high level configuring the sub-bands, or the feedback of the terminal selecting the sub-bands, the feedback further is: the terminal applying a differential mode to feed back; and wherein, the differential mode is: differentiating the channel quality indicator based on the different sub-band with the channel quality indicator based on the full bandwidth. ### Claim 6 (depends on 3) The method of claim 3, wherein, the feedback comprises: periodic feedback or aperiodic feedback; and when the periodic feedback and aperiodic feedback happen in a same sub-frame, said terminal reports the aperiodic feedback in said sub-frame. ### Claim 7 (depends on 2) The method of claim 2, wherein, the feedback further comprises: the terminal feeding back according to different feedback methods; wherein, the feedback methods comprise: full bandwidth feedback, feedback of high level configuring sub-bands or feedback of the terminal selecting sub-bands; and after the feedback, the method further comprises a determining process of modulation and encoding, and the determining process of the modulation and encoding comprises: corresponding to the different feedback methods, the primary node performing resource scheduling according to the channel quality indicator based on the full bandwidth or different sub-band and fed back by the terminal, and selecting a matching modulation and encoding method to modulate and encode data of scheduled users. ### Claim 8 (depends on 7) The method of claim 7, wherein, when the feedback method is the feedback of the high level configuring the sub-bands, or the feedback of the terminal selecting the sub-bands, the feedback further is: the terminal applying a differential mode to feed back; and wherein, the differential mode is: differentiating the channel quality indicator based on the different sub-band with the channel quality indicator based on the full bandwidth. ### Claim 9 (depends on 2) The method of claim 2, wherein, the feedback comprises: periodic feedback or aperiodic feedback; and when the periodic feedback and aperiodic feedback happen in a same sub-frame, said terminal reports the aperiodic feedback in said sub-frame. ### Claim 10 (depends on 1) The method of claim 1, wherein, the feedback further comprises: the terminal feeding back according to different feedback methods; wherein, the feedback methods comprise: full bandwidth feedback, feedback of high level configuring sub-bands or feedback of the terminal selecting sub-bands; and after the feedback, the method further comprises a determining process of modulation and encoding, and the determining process of the modulation and encoding comprises: corresponding to the different feedback methods, the primary node performing resource scheduling according to the channel quality indicator based on the full bandwidth or different sub-band and fed back by the terminal, and selecting a matching modulation and encoding method to modulate and encode data of scheduled users. ### Claim 11 (depends on 10) The method of claim 10, wherein, when the feedback method is the feedback of the high level configuring the sub-bands, or the feedback of the terminal selecting the sub-bands, the feedback further is: the terminal applying a differential mode to feed back; and wherein, the differential mode is: differentiating the channel quality indicator based on the different sub-band with the channel quality indicator based on the full bandwidth. ### Claim 12 (depends on 1) The method of claim 1, wherein, the feedback comprises: periodic feedback or aperiodic feedback; and when the periodic feedback and aperiodic feedback happen in a same sub-frame, said terminal reports the aperiodic feedback in said sub-frame. ### Claim 13 A system of channel quality indicator feedback, comprising a feedback unit at a terminal side, and a modulation and encoding determination unit at a primary node side; wherein, said feedback unit is used in a multi-point coordinated transmission and reception (CoMP) system to calculate and feed back a channel quality indicator corresponding to a comprehensive channel formed between the terminal and all transmission nodes in a CoMP active transmission point set, or each channel quality indicator corresponding to each channel between each transmission node and the terminal; and said modulation and encoding determination unit is used to determine a modulation and encoding method corresponding to downlink data transmission according to content fed back by the terminal; wherein, in the CoMP active transmission point set, different transmission nodes apply the same modulation and encoding method. ### Claim 14 (depends on 13) The system of claim 13, wherein, the feedback unit is further used to feed back a channel quality indicator corresponding to a channel between the primary node and the terminal to the primary node; and feed back the channel quality indicator corresponding to the comprehensive channel to the primary node, or respectively feed back to the primary node each channel quality indicator of each channel formed between each non-primary node except the primary node in the CoMP active transmission point set and the terminal. ### Claim 15 (depends on 13) The system of claim 13, wherein, the feedback unit is further used to feed back according to different feedback methods; and wherein, said feedback methods comprise: full bandwidth feedback, feedback of high level configuring sub-bands or feedback of the terminal selecting sub-bands. ### Claim 16 (depends on 15) The system of claim 15, wherein, the modulation and encoding unit is further used to, corresponding to the different feedback methods, perform resource scheduling according to the channel quality indicator based on the full bandwidth or different sub-band and fed back by the terminal, and select a matching modulation and encoding method to modulate and encode. ### Claim 17 (depends on 13) The system of claim 13, wherein, the feedback unit is further used to perform periodic feedback or aperiodic feedback; and when the periodic feedback and the aperiodic feedback happen in a same sub-frame, the terminal reports the aperiodic feedback to said sub-frame.