# US 11,121,834 B2 · Aperiodic and periodic CSI feedback modes for coordinated multi-point transmission

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- Number: US 11,121,834 B2
- Document ID: US11121834B2
- Status: Granted
- Kind: B2
- Application number: 13/920,872
- Filed: 2013-06-18
- Published: 2013-12-19
- Granted: 2021-09-14
- Earliest claimed: 2013-06-18
- Assignees: Samsung Electronics Co., Ltd.
- Applicants: Samsung Electronics Co., Ltd.
- Inventors: Krishna Sayana; Boon Loong Ng; Young-Han Nam; Thomas Novlan; Jinkyu Han; Jianzhong Zhang; Hyojin Lee; Youn-Sun Kim
- Web page: https://patentgrep.com/patent/US11121834B2

## CPC

- H04L 5/0035: {Resource allocation in a cooperative multipoint environment}
- 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 7/063: {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]}
- 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 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals}
- H04L 43/06: Generation of reports
- H04W 72/21: in the uplink direction of a wireless link, i.e. towards the network
- H04W 72/542: using measured or perceived quality
- H04B 7/0647: {Variable feedback rate}
- 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

Coordinate multi-point (CoMP) transmission is facilitated by resolving collisions between feedback reporting. Based upon the conditions within the network, collision resolution may be by dropping a channel report during a subframe, multiplexing channel reports from a plurality of user equipment, compressing channel reports a plurality of user equipment, and combined reporting, either through joint reports or by using carrier aggregation, for conditions between a user equipment and a plurality of transmission points. New signaling and reporting formats facilitate selection of a collision resolution suitable for current network conditions.

## Claims

### Claim 1

A user equipment, comprising:
a transceiver configured to receive a signal containing information regarding configuration of at least two channel state information (CSI) processes,
wherein a first of the at least two CSI processes corresponds to a first CSI reporting configuration associated with a first set of CSI report parameters determined based on a first CSI-reference signal (CSI-RS) resource and a first CSI-interference measurement,
wherein the first of the at least two CSI processes is used for generating a first CSI report,
wherein a second of the at least two CSI processes is identified by a CSI process identifier and is a rank indicator (RI)-reference CSI process, where an RI determined by the second CSI process is also used for aligned CSI processes, and
wherein the first CSI process is aligned with the RI-reference CSI process by a CSI process configuration parameter in the configuration for the first CSI process, the CSI process configuration parameter indicating the CSI process identifier of the second CSI process; and
a controller configured to determine the configurations of the at least two CSI processes from the received signal and use the first CSI reporting configuration to generate the first CSI report including the RI determined by the second CSI process.

### Claim 2 (depends on 1)

The user equipment according to claim 1, wherein the first CSI report comprises information determined based on at least one CSI reference signal (CSI-RS), and wherein the CSI process configuration parameter is a Rank_Reference_Process parameter.

### Claim 3 (depends on 1)

The user equipment according to claim 1, wherein the RI defined for the RI-reference CSI process is applied for CSI reporting by the user equipment to all of two or more transmission points.

### Claim 4 (depends on 1)

The user equipment according to claim 1, wherein the first CSI report comprises a periodic CSI report.

### Claim 5 (depends on 1)

The user equipment according to claim 1, wherein the first CSI report comprises an aperiodic CSI report.

### Claim 6

A user equipment, comprising:
a control system configured to report channel state information (CSI) to each of two or more transmission points from which the user equipment is receiving signals using at least two channel state information (CSI) processes,
wherein a first of the at least two CSI processes corresponds to a first CSI reporting configuration associated with a first set of CSI report parameters determined based on a first CSI-reference signal (CSI-RS) resource and a first CSI-interference measurement,
wherein the first of the at least two CSI processes is used for generating a CSI report,
wherein a second of the at least two CSI processes is identified by a CSI process identifier and is a rank indicator (RI)-reference CSI process, where an RI determined by the second CSI process is also used for aligned CSI processes,
wherein the first CSI process is aligned with the RI-reference CSI process by a CSI process configuration parameter in the configuration for the first CSI process, the CSI process configuration parameter indicating the CSI process identifier of the second CSI process,
wherein, in response to a collision between at least two CSI reports to different ones of the two or more transmission points each with reporting type of a same priority and employing different CSI processes, the control system is configured to drop one of the at least two CSI reports based upon configuration indices associated with the CSI processes for the two CSI reports, and
wherein, in response to a collision between at least two CSI reports to different ones of the two or more transmission points each with reporting type of a same priority and employing a same CSI measurement process, the control system is configured to drop one of the at least two CSI reports based upon indices associated the two or more transmission points.

### Claim 7 (depends on 6)

The user equipment according to claim 6, wherein one or more of the at least two CSI reports other than the one of the at least two CSI reports corresponding to a lowest RI-reference CSI process is dropped.

### Claim 8 (depends on 6)

The user equipment according to claim 6, wherein the one of the at least two CSI reports corresponding to a lowest CSI configuration index is dropped.

### Claim 9 (depends on 6)

The user equipment according to claim 6, wherein all of the at least two CSI reports are dropped except for one of the at least two CSI reports corresponding to a lowest CSI configuration index.

### Claim 10 (depends on 6)

The user equipment according to claim 6, wherein the first CSI report comprises a periodic CSI report.

### Claim 11

A base station, comprising:
a transceiver configured to transmit a signal containing information regarding configuration of at least two channel state information (CSI) processes,
wherein a first of the at least two CSI processes corresponds a first CSI reporting configuration associated with a first set of CSI report parameters determined based on a first CSI-reference signal (CSI-RS) resource and a first CSI-interference measurement,
wherein the first of the at least two CSI processes is used for generating a first CSI report,
wherein a second of the at least two CSI processes is identified by a CSI process identifier and is a rank indicator (RI)-reference CSI process, where an RI determined by the second CSI process is also used for aligned CSI processes, and
wherein the first CSI process is aligned with the RI-reference CSI process by a CSI process configuration parameter in the configuration for the first CSI process, the CSI process configuration parameter indicating the CSI process identifier of the second CSI process; and
a controller configured to determine, from a received CSI report, CSI for a first of the at least two CSI processes.

### Claim 12 (depends on 11)

The base station according to claim 11, wherein the first CSI report comprises information determined based on at least one CSI reference signal (CSI-RS), and wherein the CSI process configuration parameter is a Rank_Reference_Process parameter.

### Claim 13 (depends on 11)

The base station according to claim 11, wherein the RI identified for the RI-reference CSI process is applied for CSI reporting by a user equipment to all of two or more transmission points.

### Claim 14 (depends on 11)

The base station according to claim 11, wherein the first CSI report comprises a periodic CSI report.

### Claim 15 (depends on 11)

The base station according to claim 11, wherein the first CSI report comprises an aperiodic CSI report.

### Claim 16

A base station, comprising:
a control system configured to receive channel state information (CSI) reports from a user equipment reporting CSI to each of two or more transmission points from which the user equipment is receiving signals using at least two CSI processes,
wherein a first of the at least two CSI process corresponds to a first CSI reporting configuration associated with a first set of CSI report parameters determined based on a first CSI-reference signal (CSI-RS) resource and a first CSI-interference measurement,
wherein the first of the at least two CSI processes is used for generating a CSI report,
wherein a second of the at least two CSI processes is identified by a CSI process identifier and is a rank-indicator (RI)-reference CSI process, where an RI determined by the second CSI process is also used for aligned CSI processes,
wherein the first CSI process is aligned with the RI-reference CSI process by a CSI process configuration parameter in the configuration for the first CSI process, the CSI process configuration parameter indicating the CSI process identifier of the second CSI process,
wherein in response to a collision between at least two CSI reports from the user equipment to different ones of the two or more transmission points each with reporting type of a same priority and employing different CSI processes, a received one of the at least two CSI reports is based upon configuration indices associated with the CSI processes for the two CSI reports and,
wherein in response to a collision between at least two CSI reports from the user equipment to different ones of the two or more transmission points each with reporting type of a same priority and employing a same CSI process, a received one of the at least two CSI reports is based upon indices associated with the two or more transmission points.

### Claim 17 (depends on 16)

The base station according to claim 16, wherein the received one of the at least two CSI reports corresponds to a lowest RI-reference CSI process index.

### Claim 18 (depends on 16)

The base station according to claim 16, wherein the received one of the at least two CSI reports corresponds to a lowest of two CSI configuration indices associated with two CSI reports of the at least two CSI reports.

### Claim 19 (depends on 16)

The base station according to claim 16, wherein the received one of the at least two CSI reports corresponds to a lowest of all CSI configuration indices associated with the at least two CSI reports.

### Claim 20 (depends on 16)

The base station according to claim 16, wherein the first CSI report comprises a periodic CSI report.

### Claim 21

A method, comprising:
receiving, in a user equipment, a signal containing information regarding configuration of at least two channel state information (CSI) processes,
wherein a first of the at least two CSI processes corresponds to a first CSI reporting configuration associated with a first set of CSI report parameters determined based on a first CSI-reference signal (CSI-RS) resource and a first CSI-interference measurement,
wherein the first of the at least two CSI processes is used for generating a first CSI report, and
wherein a second of the at least two CSI processes is identified by a CSI process identifier and is a rank indicator (RI)-reference CSI process, where an RI determined by the second CSI process is also used for aligned CSI processes, and
wherein the first CSI process is aligned with the RI-reference CSI process by a CSI process configuration parameter in the configuration for the first CSI process, the CSI process configuration parameter indicating the CSI process identifier of the second CSI process;
determining, in the user equipment, the configurations of the at least two CSI processes from the received signal; and
using the first CSI reporting configuration to generate the first CSI report including the RI determined by the second CSI process.

### Claim 22 (depends on 21)

The method according to claim 21, wherein the first CSI report comprises information determined based on at least one CSI reference signal (CSI-RS), and wherein the CSI process configuration parameter is a Rank_Reference_Process parameter.

### Claim 23 (depends on 21)

The method according to claim 21, wherein the RI identified for the RI-reference CSI process is applied for CSI reporting by the user equipment to all of two or more transmission points.

### Claim 24 (depends on 21)

The method according to claim 21, wherein the first CSI report comprises a periodic CSI report.

### Claim 25 (depends on 21)

The method according to claim 21, wherein the first CSI report comprises an aperiodic CSI report.

### Claim 26

A method, comprising:
reporting, from a user equipment, channel state information (CSI) to each of two or more transmission points from which the user equipment is receiving signals using at least two CSI processes,
wherein a first of the at least two CSI processes corresponds to a first CSI reporting configuration associated with a first set of CSI report parameters determined based on a first CSI-reference signal (CSI-RS) resource and a first CSI-interference measurement,
wherein the first of the at least two CSI processes is used for generating a first CSI report,
wherein a second of the at least two CSI processes is identified by a CSI process identifier and is a rank indicator (RI)-reference CSI process, where an RI determined by the second CSI process is also used for aligned CSI processes,
wherein the first CSI process is aligned with the RI-reference CSI process by a CSI process configuration parameter in the configuration for the first CSI process, the CSI process configuration parameter indicating the CSI process identifier of the second CSI process;
in response to a collision between at least two CSI reports from the user equipment to different ones of the two or more transmission points each with reporting type of a same priority and employing different CSI processes, dropping, at the user equipment, one of the at least two CSI reports based upon configuration indices associated with the two CSI reports; and
in response to a collision between at least two CSI reports to different ones of the two or more transmission points each with reporting type of a same priority and employing a same CSI process, dropping, at the user equipment, one of the at least two CSI reports based upon indices associated the two or more transmission points.

### Claim 27 (depends on 26)

The method according to claim 26, wherein one or more of the at least two CSI reports other than the one of the at least two CSI reports corresponding to a lowest RI-reference CSI process is dropped.

### Claim 28 (depends on 26)

The method according to claim 26, wherein the one of the at least two CSI reports corresponding to a lowest CSI configuration index is dropped.

### Claim 29 (depends on 26)

The method according to claim 26, wherein all of the at least two CSI reports are dropped except for one of the at least two CSI reports corresponding to a lowest CSI configuration index.

### Claim 30 (depends on 26)

The method according to claim 26, wherein the first CSI report comprises a periodic CSI report.