# US 8,543,150 B2 · Clustering method and communication device for coordinated multipoint transmission > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,543,150 B2 - Document ID: US8543150B2 - Status: Granted - Kind: B2 - Application number: 12/637,784 - Filed: 2009-12-15 - Published: 2010-12-02 - Granted: 2013-09-24 - Earliest claimed: 2009-05-29 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Hyun Ho Choi; Kyung Hun Jang; Hyo Sun Hwang; Jong Bu Lim - Inventors: Hyun Ho Choi; Kyung Hun Jang; Hyo Sun Hwang; Jong Bu Lim - Web page: https://patentgrep.com/patent/US8543150B2 ## CPC - H04W 72/542: using measured or perceived quality - 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 - H04W 72/20: Control channels or signalling for resource management - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04B: TRANSMISSION ## Abstract A communication system performing a coordinated multipoint transmission is provided. A mobile station may measure expected channel quality information when an interference of a serving base station does not exist. The serving base station may determine whether a neighbor base station and the serving base station are eligible to perform the coordinated multipoint transmission. The serving base station may determine whether the neighbor base station and the serving base station are eligible to perform the coordinated multipoint transmission using a criterion associated with an evaluation of an increase in a transmission rate of the mobile station. ## Claims ### Claim 1 A method of clustering a coordinated multipoint transmission of a serving base station, the method comprising: emptying a resource element of the serving base station that corresponds to a signal transmitted from a neighbor base station to a mobile station, before the mobile station computes expected channel quality information of the signal transmitted from the neighbor base station to the mobile station; receiving, from the mobile station, channel quality information of a signal transmitted from the serving base station to the mobile station, and the expected channel quality information; comparing the channel quality information with the expected channel quality information; and determining whether the neighbor base station is eligible to perform the coordinated multipoint transmission with the serving base station based on a result of the comparing. ### Claim 2 (depends on 1) The clustering method of claim 1, wherein the determining comprises: checking whether a criterion, associated with an evaluation of an increase in a transmission rate of the mobile station according to the coordinated multipoint transmission, is satisfied based on the result of the comparing; and determining whether the neighbor base station is eligible to perform the coordinated multipoint transmission based on a result of the checking. ### Claim 3 (depends on 1) The clustering method of claim 1, wherein the determining comprises: predicting an increase in a transmission rate of the mobile station according to the coordinated multipoint transmission based on the result of the comparing; and determining whether the neighbor base station is eligible to perform the coordinated multipoint transmission based on the predicted increase in the transmission rate. ### Claim 4 (depends on 1) The clustering method of claim 1, wherein, when the coordinated multipoint transmission is performed in a plurality of modes, the determining comprises: checking whether a criterion, associated with an evaluation of an increase in a transmission rate according to a change from a current mode of the coordinated multipoint transmission to a particular mode, is satisfied based on the result of the comparing; and determining whether the neighbor base station is eligible to perform the coordinated multipoint transmission in the particular mode based on a result of the checking. ### Claim 5 (depends on 1) The clustering method of claim 1, wherein the mobile station computes the expected channel quality information based on the signal transmitted by the neighbor base station in a radio resource region that is not used by the serving base station. ### Claim 6 (depends on 1) The clustering method of claim 1, wherein the determining comprises: providing a weight to the expected channel quality information, or the channel quality information, or any combination thereof. ### Claim 7 (depends on 1) The clustering method of claim 1, wherein the receiving comprises: acquiring periodically the expected quality information, or acquiring the expected channel quality information after instructing the mobile station to report the expected channel quality information. ### Claim 8 (depends on 1) The clustering method of claim 1, further comprising: providing, by the serving base station, the mobile station with information about the neighbor base station to enable the mobile station to compute the expected channel quality information. ### Claim 9 (depends on 1) The clustering method of claim 1, further comprising: instructing, by the serving base station, the mobile station to report the expected channel quality information based on the channel quality information. ### Claim 10 (depends on 1) The clustering method of claim 1, further comprising: providing the mobile station with scheduling information to perform the coordinated multipoint transmission, or cell information of the coordinated multipoint transmission, when the neighbor base station is determined to be eligible to perform the coordinated multipoint transmission with the serving base station. ### Claim 11 (depends on 1) The clustering method of claim 1, wherein: the expected channel quality information comprises information about a signal to interference plus noise ratio of the signal transmitted from the neighbor base station to the mobile station; and the mobile station computes the signal to interference plus noise ratio when an interference of the serving base station with respect to the neighbor base station is non-existent in substance or removed. ### Claim 12 (depends on 1) The clustering method of claim 1, wherein the comparing comprises: determining whether the expected channel quality information, or the expected channel quality information subtracted by one, is greater than or equal to the channel quality information. ### Claim 13 A method of clustering a coordinated multipoint transmission of a serving base station, the method comprising: emptying a resource element of the serving base station that corresponds to a signal transmitted from a neighbor base station to a mobile station, before the mobile station computes expected channel quality information of the signal transmitted from the neighbor base station to the mobile station; obtaining, from the mobile station, channel quality information of a signal transmitted from the serving base station to the mobile station, and the expected channel quality information; comparing the channel quality information with the expected channel quality information; checking whether a first criterion, associated with an evaluation of an increase in a transmission rate according to the coordinated multipoint transmission of the neighbor base station and the serving base station, or a second criterion, associated with an evaluation of an increase in a transmission rate according to a change from a current mode of the coordinated multipoint transmission to a particular mode, is satisfied based on a result of the comparing; and determining whether the neighbor base station is eligible to perform the coordinated multipoint transmission with the serving base station, or whether the neighbor base station is eligible to perform the coordinated multipoint transmission in the particular mode, based on a result of the checking. ### Claim 14 (depends on 13) The clustering method of claim 13, wherein the mobile station computes the expected channel quality information based on the signal transmitted by the neighbor base station in a radio resource region that is not used by the serving base station. ### Claim 15 An operation method of a mobile station for a coordinated multipoint transmission, the method comprising: computing expected channel quality information of a signal transmitted from a neighbor base station to the mobile station, in response to a serving base station emptying a resource element of the serving base station that corresponds to the signal transmitted from the neighbor base station to the mobile station; and reporting, to the serving base station, channel quality information of a signal transmitted from the serving base station to the mobile station, and the expected channel quality information, to enable the serving base station to compare the channel quality information with the expected channel quality information, and determine whether the neighbor base station and the serving base station perform the coordinated multipoint transmission based on a result of the comparison. ### Claim 16 (depends on 15) The operation method of claim 15, wherein the reporting comprises: reporting the expected channel quality information based on the channel quality information. ### Claim 17 (depends on 15) The operation method of claim 15, wherein the computing comprises: computing the expected channel quality information based on the signal transmitted by the neighbor base station in a radio resource region that is not used by the serving base station. ### Claim 18 (depends on 15) The operation method of claim 15, further comprising: receiving scheduling information to perform the coordinated multipoint transmission, or cell information of the coordinated multipoint transmission, when the neighbor base station and the serving base station are determined to perform the coordinated multipoint transmission. ### Claim 19 (depends on 15) The operation method of claim 15, wherein the reporting comprises: reporting the expected channel quality information using a predetermined feedback control channel. ### Claim 20 (depends on 15) The operation method of claim 15, wherein the computing comprises: computing the expected channel quality information in a resource element of the neighbor base station that is used to transmit the signal from the neighbor base station to the mobile station. ### Claim 21 An operation method of a mobile station for a coordinated multipoint transmission, the method comprising: computing expected channel quality information of a signal transmitted from a neighbor base station to the mobile station, in response to an interference of a serving base station with respect to the neighbor base station being non-existent in substance or removed; and reporting, to the serving base station, channel quality information of a signal transmitted from the serving base station to the mobile station, and the expected channel quality information using a predetermined feedback control channel, to enable the serving base station to compare the channel quality information with the expected channel quality information, and determine whether the neighbor base station and the serving base station perform the coordinated multipoint transmission based on a result of the comparison, wherein the serving base station assigns a radio resource used to report the expected channel quality information using the predetermined feedback control channel. ### Claim 22 A non-transitory computer-readable storage medium storing a program to implement a method of clustering a coordinated multipoint transmission of a serving base station, the method comprising: emptying a resource element of the serving base station that corresponds to a signal transmitted from a neighbor base station to a mobile station, before the mobile station computes expected channel quality information of the signal transmitted from the neighbor base station to the mobile station; receiving, from the station, channel quality information of a signal transmitted from the serving base station to the mobile station, and the expected channel quality information; comparing the channel quality information with the expected channel quality information; and determining whether the neighbor base station is eligible to perform the coordinated multipoint transmission with the serving base station based on a result of the comparing.