# US 9,882,690 B2 · Method and apparatus for transmitting information about a channel in a 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 9,882,690 B2 - Document ID: US9882690B2 - Status: Granted - Kind: B2 - Application number: 15/276,901 - Filed: 2016-09-27 - Published: 2017-01-19 - Granted: 2018-01-30 - Earliest claimed: 2009-06-09 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Hyung Tae Kim; Han Byul Seo; Ki Jun Kim; Byoung Hoon Kim - Web page: https://patentgrep.com/patent/US9882690B2 ## CPC - H04L 5/0035: {Resource allocation in a cooperative multipoint environment} - H04B 7/063: {Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection} - 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} - H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)} - H04L 5/005: {of common pilots, i.e. pilots destined for multiple users or terminals} - H04L 5/0051: {of dedicated pilots, i.e. pilots destined for a single user or terminal} - 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 7/0452: Multi-user MIMO systems - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04B: TRANSMISSION ## Abstract A method and a user equipment (UE) configured with one or more cells for feeding back channel information are discussed. The method according to an embodiment includes receiving information on a maximum number of ranks; transmitting first channel information generated based on rank information; and transmitting second channel information which is generated based on the same rank information as the rank information used for generating the first channel information. The maximum number of ranks is used to determine the rank information. ## Claims ### Claim 1 A method for feeding back channel information, the method comprising: receiving, by a user equipment (UE) configured with one or more cells, information on a maximum number of ranks; transmitting, by the UE, first channel information generated based on rank information; and transmitting, by the UE, second channel information which is generated based on the same rank information as the rank information used for generating the first channel information, wherein the maximum number of ranks is used to determine the rank information. ### Claim 2 (depends on 1) The method of claim 1, further comprising: receiving rank-related information determined by a base station based on the rank information. ### Claim 3 (depends on 1) The method of claim 1, wherein the second channel information includes at least one of a precoding matrix indicator (PMI) and channel quality information (CQI). ### Claim 4 (depends on 1) The method of claim 1, further comprising: determining the rank information corresponding a number of antenna layers. ### Claim 5 (depends on 1) The method of claim 1, wherein: the transmission of the first channel information is associated with a first feedback process, and the transmission of the second channel information is associated with a second feedback process. ### Claim 6 (depends on 5) The method of claim 5, wherein: the first feedback process is related to a first reference signal, and the second feedback process is related to a second reference signal. ### Claim 7 (depends on 6) The method of claim 6, wherein each of the first and second reference signals correspond to at least one of a cell-specific reference signal (CRS) and a channel state information reference signal (CSI-RS). ### Claim 8 (depends on 1) The method of claim 1, wherein each of the first and second channel information is channel state information (CSI). ### Claim 9 (depends on 1) The method of claim 1, wherein the first channel information or the second channel information is transmitted on a Physical Uplink Control Channel (PUCCH) or a Physical Uplink Shared Channel (PUSCH). ### Claim 10 (depends on 1) The method of claim 1, wherein rank-related information is received through downlink control information (DCI) scrambled with a radio network temporary identity (RNTI). ### Claim 11 A user equipment (UE), comprising: a Radio Frequency (RF) unit configured to transmit and receive a radio signal; and a processor coupled to the RF unit and configured with one or more cells thereby performing: receiving information on a maximum number of ranks; transmitting first channel information generated based on rank information; and transmitting second channel information which is generated based on the same rank information as the rank information used for generating the first channel information, wherein the maximum number of ranks is used to determine the rank information. ### Claim 12 (depends on 11) The UE of claim 11, wherein the processor further performs: receiving rank-related information determined by a base station based on the rank information. ### Claim 13 (depends on 11) The UE of claim 11, wherein the second channel information includes at least one of a precoding matrix indicator (PMI) and channel quality information (CQI). ### Claim 14 (depends on 11) The UE of claim 11, wherein the processor further performs: determining the rank information corresponding a number of antenna layers. ### Claim 15 (depends on 11) The UE of claim 11, wherein: the transmission of the first channel information is associated with a first feedback process, and the transmission of the second channel information is associated with a second feedback process. ### Claim 16 (depends on 15) The UE of claim 15, wherein: the first feedback process is related to a first reference signal, and the second feedback process is related to a second reference signal. ### Claim 17 (depends on 16) The UE of claim 16, wherein each of the first and second reference signals correspond to at least one of a cell-specific reference signal (CRS) and a channel state information reference signal (CSI-RS). ### Claim 18 (depends on 11) The UE of claim 11, wherein each of the first and second channel information is channel state information (CSI). ### Claim 19 (depends on 11) The UE of claim 11, wherein the first channel information or the second channel information is transmitted on a Physical Uplink Control Channel (PUCCH) or a Physical Uplink Shared Channel (PUSCH). ### Claim 20 (depends on 11) The UE of claim 11, wherein rank-related information is received through downlink control information (DCI) scrambled with a radio network temporary identity (RNTI).