Timing synchronization for downlink (DL) transmissions in coordinated multipoint (CoMP) systems

Patent metadata

Field	Value
Publication number	US-9351277-B2
Application number	US-201213997232-A
Country	US
Kind code	B2
Filing date	Jun 5, 2012
Priority date	Nov 4, 2011
Publication date	May 24, 2016
Grant date	May 24, 2016

Abstract

Technology for adjusting a receiver timing of a wireless device in a Coordinated MultiPoint (CoMP) system is disclosed. One method can include the wireless device receiving a plurality of node specific reference signals (RSs) from a plurality of cooperating nodes in a coordination set of the CoMP system. The coordination set includes at least two cooperating nodes. The wireless device can estimate a composite received RS timing from a plurality of received RS timings generated from the plurality of node specific RSs. The received RS timings represent timings from the at least two cooperating nodes. The wireless device can adjust the receiver timing based on the composite received RS timing. A node specific RS can include a channel-state information reference signal (CSI-RS).

First claim

What is claimed is:

1. A method for adjusting a receiver timing of a wireless device in a Coordinated MultiPoint (CoMP) system, comprising:
receiving a plurality of node specific reference signals (RSs) at a wireless device from a plurality of cooperating nodes in a coordination set of the CoMP system, wherein the coordination set includes at least two cooperating nodes; and
estimating a composite received RS timing from a plurality of received RS timings generated from the plurality of node specific RSs, wherein the received RS timings represent timings from the at least two cooperating nodes;
adjusting the receiver timing based at least in part on the composite received RS timing; and
selecting an earliest received RS timing of the composite received RS timing, wherein the composite received RS timing is represented by

τ
PDSCH

=

min
i

⁢

(

τ

CSI
⁢

-

⁢
RS

(
i
)

)

,

where τ PDSCH is a physical downlink shared channel (PDSCH) timing, τ CSI-RS (i) is each of calculated channel-state information reference signal (CSI-RS) timings of a CoMP measurement set, min( ) is a minimum function, and i is a positive integer representing the nodes in the CoMP measurement set.

2. The method of claim 1 , wherein the node specific RS includes a channel-state information reference signal (CSI-RS).

3. The method of claim 1 , wherein the adjusted receiver timing is a time a receiver of the wireless device processes the fast Fourier transform (FFT) for a received signal.

4. The method of claim 1 , wherein estimating the composite received RS timing further comprises selecting a receiver RS timing substantially between a minimal received RS timing and a maximal received RS timing.

5. The method of claim 4 , wherein the composite received RS timing is determine by a combination of a reference signal received power (RSRP) for the cooperating nodes and the received RS timing generated from the node specific RSs of the cooperating nodes.

6. The method of claim 4 , wherein the composite received RS timing is represented by

τ
PDSCH

=

∑
i

⁢

f
⁡

(

RSRP

CSI
⁢

-

⁢
RS

(
i
)

)

⁢

τ

CSI
⁢

-

⁢
RS

(
i
)

∑
i

⁢

f
⁡

(

RSRP

CSI
⁢

-

⁢
RS

(
i
)

)

,

where τ PDSCH is a physical downlink shared channel (PDSCH) timing, τ CSI-RS (i) is each of calculated channel-state information reference signal (CSI-RS) timings of a CoMP measurement set, RSRP CSI-RS (i) is CSI-RS antenna port reference signal received power (RSRP), i is a positive integer representing the nodes in the CoMP measurement set, and f( ) is a monotonic function of function arguments.

7. The method of claim 1 , further comprising:
transmitting from the wireless device to a cooperating node a timing feedback including the composite received RS timing or a cooperating node received RS timing generated from the node specific RSs from the cooperating node.

8. The method of claim 1 , wherein the node specific RS is selected from the group consisting of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a cell specific reference signal (CRS), and a channel-state information reference signal (CSI-RS), and combinations thereof.

9. A timing estimation device for estimating a receiver timing of a wireless device in a Coordinated MultiPoint (CoMP) system, comprising:
a downlink receiving module configured to receive a plurality of node specific reference signals (RSs) at a wireless device from a plurality of cooperating nodes in a coordination set of the CoMP system, wherein the coordination set includes at least two cooperating nodes;
a timing estimator configured to estimate a composite received RS timing from a plurality of received RS timings generated from the plurality of node specific RSs and select an earliest received RS timing for the composite received RS timing and the composite received RS timing is represented by

τ
PDSCH

=

min
i

⁢

(

τ

CSI
⁢

-

Assignees

• Davydov Alexei
• Morozov Gregory
• Maltsev Alexander
• Sergeyev Vadim
• Bolotin Ilya
• Intel Corp

Inventors

• Davydov Alexei
• Morozov Gregory
• Maltsev Alexander
• Sergeyev Vadim
• Bolotin Ilya

Classifications

• H04W52/0206

  in access points, e.g. base stations · CPC title

• H04W24/02 Primary

  Arrangements for optimising operational condition · CPC title

• H04L1/0077

  Cooperative coding · CPC title

• H04W4/06

  Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services · CPC title

• H04W28/04

  Error control · CPC title