# US 2018/0323927 A1 · Reference signal acquisition

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- Number: US 2018/0323927 A1
- Document ID: US20180323927A1
- Status: Published application
- Kind: A1
- Application number: 15/970,816
- Filed: 2018-05-03
- Published: 2018-11-08
- Earliest claimed: 2017-05-05
- Assignees: QUALCOMM Incorporated
- Applicants: QUALCOMM Incorporated
- Inventors: Sumeeth NAGARAJA; Tao LUO; Sony AKKARAKARAN; Alexandros MANOLAKOS
- Web page: https://patentgrep.com/patent/US20180323927A1

## CPC

- 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 5/0057: {Physical resource allocation for CQI}
- H04L 5/0098: {Signalling of the activation or deactivation of component carriers, subcarriers or frequency bands}
- H04W 36/0072: {of resource information of target access point}
- H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals}
- H04L 5/0092: {Indication of how the channel is divided}
- 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)

## Abstract

Various aspects of the disclosure relate to techniques associated with the acquisition of reference signals. In some aspects, a network may request a user equipment (UE) to measure a timing difference between neighbor cells and use that information to generate a CSI-RS configuration. The network sends the CSI-RS configuration to the UE to enable the UE to acquire a CSI-RS from a neighbor cell. In some aspects, a network may send timing-related information to a neighbor cell and the neighbor cell uses that information to transmit a CSI-RS.

## Claims

### Claim 1

A method of communication for an apparatus, comprising:
identifying a cell that provides timing for a channel state information-reference signal (CSI-RS); and
sending an indication of the identified cell to a user equipment (UE).

### Claim 2 (depends on 1)

The method of claim 1, wherein the identified cell comprises a serving cell for the UE.

### Claim 3 (depends on 2)

The method of claim 2, wherein the CSI-RS is transmitted by a neighbor cell of the serving cell.

### Claim 4 (depends on 1)

The method of claim 1, wherein the identified cell comprises a neighbor cell of a serving cell for the UE.

### Claim 5 (depends on 4)

The method of claim 4, wherein the CSI-RS is transmitted by the neighbor cell.

### Claim 6 (depends on 1)

The method of claim 1, wherein:
the method further includes determining a CSI-RS configuration for the CSI-RS;
the CSI-RS configuration includes the indication of the identified cell; and
the sending of the indication to the UE comprises sending the CSI-RS configuration to the UE.

### Claim 7 (depends on 6)

The method of claim 6, wherein the CSI-RS configuration comprises an indication of a sub-carrier spacing of the CSI-RS.

### Claim 8 (depends on 6)

The method of claim 6, wherein the CSI-RS configuration comprises an indication of a timing difference taking into account a sub-carrier spacing between a serving cell for the UE and a cell that transmits the CSI-RS.

### Claim 9 (depends on 6)

The method of claim 6, further comprising:
determining a timing difference between a serving cell for the UE and a cell that transmits the CSI-RS,
wherein the determination of the CSI-RS configuration is based on the timing difference.

### Claim 10 (depends on 9)

The method of claim 9, wherein the timing difference comprises a symbol timing difference.

### Claim 11 (depends on 9)

The method of claim 9, wherein the timing difference comprises a slot timing difference, a mini-slot timing difference, a system frame number timing difference, or any combination thereof.

### Claim 12 (depends on 1)

The method of claim 1, wherein the determination of the timing difference comprises receiving an indication of the timing difference from the UE.

### Claim 13 (depends on 1)

The method of claim 1, further comprising:
sending a request to measure the timing difference to the UE.

### Claim 14 (depends on 1)

The method of claim 1, wherein the determination of the timing difference comprises:
receiving a first indication of the timing difference from the UE and at least one second indication of the timing difference from at least one other UE; and
generating an estimate of the timing difference based on the first indication of the timing difference and the at least one second indication of the timing difference.

### Claim 15

An apparatus for communication comprising:
a memory device; and
a processing circuit coupled to the memory device and configured to:
identify a cell that provides timing for a channel state information-reference signal (CSI-RS); and
send an indication of the identified cell to a user equipment (UE).

### Claim at position 16

16-30. (canceled)

### Claim 31

A method of communication for an apparatus, comprising:
receiving an indication of a cell that provides timing for receiving a channel state information-reference signal (CSI-RS) at a user equipment (UE); and
receiving the CSI-RS.

### Claim 32 (depends on 31)

The method of claim 31, further comprising:
determining the timing of the indicated cell,
wherein the receipt of the CSI-RS is based on the determined timing.

### Claim 33 (depends on 31)

The method of claim 31, wherein the indicated cell comprises a serving cell for the UE.

### Claim 34 (depends on 33)

The method of claim 33, wherein the CSI-RS is transmitted by a neighbor cell of the serving cell.

### Claim 35 (depends on 31)

The method of claim 31, wherein the indicated cell comprises a neighbor cell of a serving cell for the UE.

### Claim 36 (depends on 35)

The method of claim 35, wherein the CSI-RS is transmitted by the neighbor cell.

### Claim 37 (depends on 31)

The method of claim 31, wherein the receipt of the indication comprises receiving a CSI-RS configuration for the CSI-RS that includes the indication.

### Claim 38 (depends on 37)

The method of claim 37, further comprising:
decoding the CSI-RS based on the CSI-RS configuration.

### Claim 39 (depends on 38)

The method of claim 38, wherein the decoding comprises:
determining a scrambling sequence based on the CSI-RS configuration; and
decoding the CSI-RS based on the scrambling sequence.

### Claim 40 (depends on 37)

The method of claim 37, wherein the CSI-RS configuration comprises an indication of a sub-carrier spacing of the CSI-RS.

### Claim 41 (depends on 37)

The method of claim 37, wherein the CSI-RS configuration comprises an indication of a timing difference taking into account a sub-carrier spacing between a serving cell for the UE and a cell that transmits the CSI-RS.

### Claim 42 (depends on 37)

The method of claim 37, wherein the CSI-RS configuration is based on a timing difference between a serving cell for the UE and the indicated cell.

### Claim 43 (depends on 42)

The method of claim 42, further comprising:
determining the timing difference; and
sending an indication of the timing difference to the serving cell.

### Claim 44 (depends on 31)

The method of claim 31, further comprising:
conducting a mobility operation associated with the indicated cell based on the CSI-RS.

### Claim 45

An apparatus for communication comprising:
a memory device; and
a processing circuit coupled to the memory device and configured to:
receive an indication of a cell that provides timing for receiving a channel state information-reference signal (CSI-RS) at a user equipment (UE); and
receive the CSI-RS.

### Claim at position 32

46-59. (canceled)