Reference signal configuration for coordinated multipoint

• US 9,106,386 B2
• Filed: 03/12/2013
• Issued: 08/11/2015
• Est. Priority Date: 08/03/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Intel Corporation
• Inventors: Etemad, Kamran, Davydov, Alexei, Morozov, Gregory, Bolotin, Ilya
• Primary Examiner(s): Vu, Huy D
• Assistant Examiner(s): CUNNINGHAM, KEVIN M
• Application Number:
  US13/796,720
• Publication Number:
  US 20140036796A1
• Time in Patent Office: 882 Days
• US Class Current: 1/1
• CPC Class Codes: H04B 17/27 for locating or positioning the transmitter
• CPC Class Codes: H04L 1/0013 Rate matching, e.g. puncturing or repetition of code symbols
• CPC Class Codes: H04L 41/0659 by isolating or reconfiguring faulty entities
• CPC Class Codes: H04L 41/082 the condition being updates or upgrades of network functionality
• CPC Class Codes: H04L 41/0823 characterised by the purposes of a change of settings, e.g. optimising configuration for enhancing reliability for optimising operational conditions of wireless networks H04W24/02
• CPC Class Codes: H04L 41/0836 to enhance reliability, e.g. reduce downtime
• CPC Class Codes: H04L 43/0811 by checking connectivity
• CPC Class Codes: H04L 45/306 Route determination based on the nature of the carried application
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 65/613 for the control of the source by the destination control signals issued by the client directed to the server or network components specially adapted for selective content distribution H04N21/637
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04L 67/51 Discovery or management thereof, e.g. service location protocol [SLP] or web services
• CPC Class Codes: H04L 67/75 Indicating network or usage conditions on the user display
• CPC Class Codes: H04N 21/23439 for generating different versions
• CPC Class Codes: H04N 21/25825 involving client display capabilities, e.g. screen resolution of a mobile phone optimising the visualisation of content during browsing in the Internet G06F16/9577; processing of terminal status or physical abilities in wireless networks H04W8/22; authentication in wireless network security H04W12/06
• CPC Class Codes: H04W 12/06 Authentication
• CPC Class Codes: H04W 16/18 Network planning tools
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 24/04 Arrangements for maintaining operational condition
• CPC Class Codes: H04W 4/02 : Services making use of location information
• CPC Class Codes: H04W 4/70 : Services for machine-to-machine communication [M2M] or machine type communication [MTC]
• CPC Class Codes: H04W 40/20 : based on geographic position or location
• CPC Class Codes: H04W 40/246 : Connectivity information discovery
• CPC Class Codes: H04W 48/14 : using user query or user detection
• CPC Class Codes: H04W 48/18 : Selecting a network or a communication service
• CPC Class Codes: H04W 52/00 : Power management, e.g. TPC [Transmission Power Control], power saving or power classes gain control in transmitters or power amplifiers H03G3/3042
• CPC Class Codes: H04W 52/0209 : in terminal devices terminal devices per se H04W88/02
• CPC Class Codes: H04W 52/0212 : managed by the network, e.g. network or access point is master and terminal is slave
• CPC Class Codes: H04W 52/0216 : using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0229 : where the received signal is a wanted signal
• CPC Class Codes: H04W 52/0258 : controlling an operation mode according to history or models of usage information, e.g. activity schedule or time of day
• CPC Class Codes: H04W 76/10 : Connection setup
• CPC Class Codes: H04W 76/11 : Allocation or use of connection identifiers
• CPC Class Codes: H04W 76/14 : Direct-mode setup
• CPC Class Codes: H04W 76/15 : Setup of multiple wireless link connections
• CPC Class Codes: H04W 76/16 : Involving different core network technologies, e.g. a packet-switched [PS] bearer in combination with a circuit-switched [CS] bearer
• CPC Class Codes: H04W 76/28 : Discontinuous transmission [DTX]; Discontinuous reception [DRX]
• CPC Class Codes: H04W 88/06 : adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: Y02D 30/70 : in wireless communication networks

Abstract

Coordinated Multipoint (CoMP) involves multiple transmission points or cells coordinating their individual transmissions so that a target user equipment (LTE) experiences enhanced signal reception and/or reduced interference. In order to optimally implement downlink CoMP, a serving cell needs to obtain channel state information (CSI) for the downlink channels from the multiple transmission points to the UE. This disclosure deals with radio resource control (RRC) signaling for configuring the UE to obtain and report CSI for those downlink channels.

Claims

1. A user equipment (UE) device for operating in a Long Term Evolution (LTE) network, comprising:

a transceiver for providing an LTE air interface to an evolved Node B (eNB); and

,

processing circuitry connected to the transceiver and to;

receive a radio resource control (RRC) configuration message from the eNB that configures the UE to receive channel state information (CSI) reference signals (CSI-RS) transmitted from one or more coordinated multi-point (CoMP) transmission points (TPs);

wherein the RRC configuration message includes a set of indexed non-zero power (NZP) CSI-RS resources that are to be included in a CoMP measurement set, a set of zero power (ZP) CSI-RS resources, and interference measurement (IM) resources for use by the UE in making interference measurements;

receive RRC configuration messaging that configures a plurality of CSI processes for which CSI reports as derived from a specified measurement subframe set are to be transmitted to the eNB; and

,

if RRC configuration messaging indicates that CSI for a particular CSI process is to be reported using a common rank indicator (RI), a common precoding matrix indicator (PMI), or a common preferred set of subbands that indicates use by another CSI process for the same measurement subframe set, drop the RI, PMI, or preferred set of subbands from the CSI report.

2. The device of claim 1 wherein the set of IM resources is a subset of the set of ZP CSI-RS resources.

3. The device of claim 2 wherein the set of ZP CSI-RS resources is transmitted as a 16-bit bitmap with each bit corresponding to a particular CSI-RS configuration that is to be regarded as having zero transmission power and further wherein the set of IM resources is configured with a bitmap indicating which of the ZP-CSI resources are to be used for interference measurements.

4. The device of claim 1 wherein the RRC configuration message further includes an indication that one or more particular NZP CSI-RS resources is an interference measurement (IM) resource for use by the UE in making interference measurements.

5. The device of claim 1 wherein the processing circuitry is to receive RRC configuration messaging that configures one or more indexed CSI processes, where each CSI process is as a combination of a NZP CSI-RS resource, IM resource, and measurement subframe set specifying for which subframes set CSI is to be reported by the UE.

6. A base station for acting as an evolved node B (eNB) in a Long Term Evolution (LTE) network, comprising:

a transceiver for providing an LTE air interface to a plurality terminals; and

,

processing circuitry connected to the transceiver and to;

act as a serving cell to a user equipment (UE) and act as one of a plurality of cooperating coordinated multi-point (CoMP) transmission points (TPs) for the UE;

configure the UE to receive channel state information (CSI) reference signals (CSI-RS) transmitted from one or more of the cooperating TPs by transmitting a radio resource control (RRC) configuration message to the UE;

wherein the RRC configuration message includes a set of indexed non-zero power (NZP) CSI-RS resources that are to be included in a CoMP measurement set, a set of zero power (ZP) CSI-RS resources, and a set of indexed interference measurement (IM) resources for use by the UE in making interference measurements;

wherein the set of IM resources is a subset of the set of ZP CSI-RS resources;

transmit RRC configuration messaging to the UE that configures a plurality of CSI processes for which CSI reports as derived from a specified measurement subframe set are to be transmitted to the eNB; and

,

transmit an RRC message instructing the UE to drop a rank indicator (RI), a precoding matrix indicator (PMI), or preferred set of subbands from the CSI report for a particular CSI process if the RI, PMI, or preferred set of subbands is reported by a another CSI process for the same measurement subframe set.

7. The base station of claim 6 wherein the RRC message further includes subframe configuration periods including subframe offsets for separately specifying the periodicity of the NZP CSI-RS, IM resources, and the ZP CSI-RS.

8. The base station of claim 6 wherein the set of ZP CSI-RS resources is transmitted as a bitmap with each bit corresponding to a particular CSI-RS configuration that is to be regarded as having zero transmission power and further wherein the set of IM resources is configured with a bitmap indicating which of the ZP-CSI resources are to be used for interference measurements.

9. The base station of claim 8 wherein the set of IM resources is configured with a bitmap with each bit corresponding to a particular group of four resource elements (REs) belonging to the set of ZP CSI-RS or is configured with a bitmap with each bit corresponding to a particular resource element (RE) pair belonging to the set of ZP CSI-RS resources.

10. The base station of claim 6 wherein the set of IM resources is configured as a particular CSI-RS configuration with four antenna ports whose resources are to be used by the UE for interference measurement or is configured as a particular CSI-RS configuration with two antenna ports whose resources are to be used by the UE for interference measurement.

11. The base station of claim 6 wherein the processing circuitry is to transmit explicit indexes of the NZP CSI-RS resources in the RRC message.

12. The base station of claim 6 wherein the processing circuitry is to implicitly indicate the indexes of the NZP CSI-RS resources by their order of configuration in the RRC message.

13. A base station for acting as an evolved node B (eNB) in a Long Term Evolution (LTE) network, comprising:

a transceiver for providing an UE air interface; and

processing circuitry connected to the transceiver and to;

act as a serving cell to a user equipment (UE) and act as one of a plurality of cooperating coordinated multi-point (CoMP) transmission points (TPs) for the UE;

configure the UE to receive channel state information (CSI) reference signals (CSI-RS) transmitted from one or more of the cooperating TPs by transmitting a radio resource control (RRC) configuration message to the UE;

wherein the RRC configuration message includes a set of indexed non-zero power (NZP) CSI-RS resources that are to be included in a CoMP measurement set and a set of zero power (ZP) CSI-RS resources;

wherein the RRC configuration message further includes an indication that one or more particular NZP CSI-RS resources is an interference measurement (IM) resource for use by the UE in making interference measurements;

configure a plurality of indexed CSI processes via RRC messaging, where each CSI process is as a combination of a NZP CSI-RS resource, and IM resource, and a measurement subframe set specifying for which subframes CSI is to be reported by the UE; and

,

configure the UE to transmit CSI reports concatenated in increasing order of CSI process index and, for each CSI process index when carrier aggregation is configured, concatenated in increasing order of cell index.

14. The base station of claim 13 wherein the processing circuitry is to transmit an RRC message including configuration of multiple indexed IM resources for enabling interference measurements by the UE for multiple interference hypotheses.

15. The base station of claim 14 wherein the processing circuitry is to transmit explicit indexes of the IM resources in the RRC message.

16. The base station of claim 14 wherein the processing circuitry is to implicitly indicate indexes of the IM resources by their order of configuration in the RRC message.

17. The base station of claim 13 wherein the processing circuitry is to transmit explicit indexes of the NZP CSI-RS resources in the RRC message.

18. The base station of claim 13 wherein the processing circuitry is to implicitly indicate indexes of the NZP CSI-RS resources by their order of configuration in the RRC message.

19. A method for operating an evolved node B (eNB) in a Long Term Evolution (LTE) network, comprising:

acting as a serving cell to a user equipment (UE) and acting as one of a plurality of cooperating coordinated multi-point (CoMP) transmission points (TPs) for the UE;

configuring the UE to receive channel state information (CSI) reference signals (CSI-RS) transmitted from one or more of the cooperating TPs by transmitting a radio resource control (RRC) configuration message to the UE;

wherein the RRC configuration message includes a set of indexed non-zero power (NZP) CSI-RS resources that are to be included in a CoMP measurement set, a set of zero power (ZP) CSI-RS resources, and an indexed set of interference measurement (IM) resources for use by the UE in making interference measurements;

configuring a plurality of indexed CSI processes via RRC messaging, where each CSI process is as a combination of a NZP CSI-RS resource, and IM resource, and a measurement subframe set specifying for which subframes CSI is to be reported by the UE; and

,

configuring the UE to transmit CSI reports concatenated in increasing order of CSI process index and, for each CSI process index when carrier aggregation is configured, concatenated in increasing order of cell index.

20. The method of claim 19 further comprising configuring two or more CSI processes such that CSI is to be reported using a common rank indicator (RI), a common precoding matrix indicator (PMI), or a common preferred set of subbands.

21. The method of claim 19 further comprising, if carrier aggregation is configured, configuring the one or more indexed CSI processes with a cell index indicating for which component carrier the CSI process is defined.

22. The method of claim 21 wherein the CSI process index is unique across multiple component carriers.

23. The method of claim 21 wherein the CSI process index is unique within each configured component carrier.

24. The method of claim 21 wherein the CSI process index is equal to a default value when only one CSI process on the component carrier or a transmission mode not supporting CoMP can be configured.

25. The method of claim 19 further comprising configuring each CSI process with a set of restricted PMIs for reporting CSI.

26. The method of claim 19 further comprising configuring aperiodic CSI process sets via an RRC message with a bit string where each bit of the bit string corresponds to a CSI process index and indicates whether or not CSI is to be reported by the UE when a corresponding trigger is received.