# US 12,004,146 B2 · Dynamic channel state information reference signals (CSI-RS) resource mapping configuration for precoded channel state information reference signals (CSI-RS) configurations

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- Number: US 12,004,146 B2
- Document ID: US12004146B2
- Status: Granted
- Kind: B2
- Application number: 17/218,864
- Filed: 2021-03-31
- Published: 2021-12-09
- Granted: 2024-06-04
- Earliest claimed: 2020-06-04
- Assignees: Nokia Technologies Oy
- Applicants: Nokia Technologies Oy
- Inventors: Rana Ahmed Salem; Eugene Visotsky; Salah Eddine Hajri; Frederick Vook; Marco Maso; William Hillery; Filippo Tosato
- Web page: https://patentgrep.com/patent/US12004146B2

## CPC

- H04L 5/0023: {Time-frequency-space}
- H04W 72/1263: Mapping of traffic onto schedule, e.g. scheduled allocation or multiplexing of flows
- H04B 7/0626: {Channel coefficients, e.g. channel state information [CSI]}
- H04B 7/06952: {Selecting one or more beams from a plurality of beams, e.g. beam training, management or sweeping}
- H04L 1/1614: {using bitmaps}
- 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}
- H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals}
- H04L 5/0091: {Signalling for the administration of the divided path, e.g. signalling of configuration information}
- H04L 5/0094: {Indication of how sub-channels of the path are allocated}
- H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal
- H04W 76/27: Transitions between radio resource control [RRC] states
- H04W 80/02: Data link layer protocols
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- 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

Dynamic and partial sharing of the channel measurement downlink reference signal resources are provided. An apparatus performs determining information relating to an actual number of ports configured for a user equipment for channel measurements and determining a pool of channel state information reference signal resources for the user equipment. The pool of channel state information reference signal resources is provided in a radio resource control configuration and includes an excess number of ports compared to the actual number of ports. The apparatus also transmits to the user equipment via at least one of a medium access control control element or downlink control information, configured user equipment specific mapping for the pool of channel state information reference signal resources.

## Claims

### Claim 1

A method, comprising:
determining, at a network node, information relating to an actual number of ports configured for a user equipment for channel measurements;
determining a pool of channel state information reference signal (CSI-RS) resources for the user equipment, wherein the pool of channel state information reference signal (CSI-RS) resources is provided in a radio resource control (RRC) configuration and includes an excess number of ports compared to the actual number of ports; and
transmitting to the user equipment an RRC configuration comprising a list of a plurality of N possible CSI-RS resource mappings, a medium access (MAC) control element (CE) comprising a plural subset Nα of the plurality of N possible CSI-RS resource mappings that are activated, and downlink control information (DCI) comprising an indication of which of the plural subset Nα of active resource mappings is to be selected as configured user equipment specific mapping for the pool of channel state information reference signal (CSI-RS) resources, wherein the user equipment specific mapping is performed over different sub-groups of CSI-RS resources and the different sub-groups of CSI-RS resources are updated at different times.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the transmitting comprises transmitting the updated or first time user equipment specific mapping using at least one of:
a bit-map;
combinatorial indexing; or
explicit configuration of indices.

### Claim 3 (depends on 1)

The method according to claim 1, further comprising informing the user equipment of the actual number of ports.

### Claim 4 (depends on 1)

The method according to claim 1, wherein the user equipment specific mapping is provided in the RRC configuration, activated in the MAC CE and selected in the DCI, and wherein the sizes of the sub-groups of resources are predefined.

### Claim 5 (depends on 1)

The method according to claim 1, wherein the user equipment specific mapping corresponds to user equipment specific ports on one polarization.

### Claim 6 (depends on 1)

The method according to claim 1, wherein the user equipment specific mapping is determined based on a default mapping provided in the RRC configuration.

### Claim 7

A method, comprising:
determining, at a network node, information relating to an actual number of ports configured for a user equipment for channel measurements;
determining a pool of channel state information reference signal (CSI-RS) resources for the user equipment, wherein the pool of channel state information reference signal (CSI-RS) resources is provided in a radio resource control (RRC) configuration and includes the actual number of ports; and
transmitting, to the user equipment, an RRC configuration comprising a list of a plurality of N possible CSI-RS resource mappings, a medium access (MAC) control element (CE) comprising a plural subset Nα of the plurality of N possible CSI-RS resource mappings that are activated, and downlink control information (DCI) comprising an indication of which of the plural subset Nα of active resource mappings is to be selected as an existing resource mapping, and transmitting one or two shift values by which the user equipment learns that the user equipment should shift the existing resource mapping in frequency and/or time inside the physical resource block (PRB), wherein the resource mapping is performed over different sub-groups of CSI-RS resources and the different sub-groups of CSI-RS resources are updated at different times.

### Claim 8 (depends on 7)

The method according to claim 7, wherein the transmitting comprises transmitting the updated or first time user equipment specific mapping using at least one of:
a bit-map;
combinatorial indexing; or
explicit configuration of indices.

### Claim 9 (depends on 7)

The method according to claim 7, wherein the user equipment specific mapping is provided in the RRC configuration, activated in the MAC CE and selected in the DCI, and wherein the sizes of the sub-groups of resources are predefined.

### Claim 10 (depends on 7)

The method according to claim 7, wherein the user equipment specific mapping corresponds to user equipment specific ports on one polarization.

### Claim 11

A method, comprising:
receiving, from a network node, fixed channel state information reference signal (CSI-RS) mapping in radio resource control (RRC), wherein the radio resource control (RRC) comprises a list of a plurality of N possible CSI-RS resource mappings;
receiving, from the network node, a medium access (MAC) control element (CE) comprising a plural subset Nα of the plurality of N possible CSI-RS resource mappings that are activated, downlink control information (DCI) comprising an indication of which of the plural subset Nα of active resource mappings is to be selected as a first channel state information reference signal (CSI-RS) mapping, and updated user equipment specific offset from the medium access control (MAC)-control element (CE) or the downlink control information (DCI) and computing new channel state information reference signal (CSI-RS) mapping, wherein the new channel state information reference signal (CSI-RS) mapping is performed over different sub-groups of CSI-RS resources and the different sub- groups of CSI-RS resources are updated at different times;
using the new channel state information reference signal (CSI-RS) mapping to receive channel state information reference signal (CSI-RS) on new locations and obtaining an estimate of channel frequency response (CFR);
deriving channel state information (CSI) feedback report from the CFR; and
providing CSI feedback information to the network node.