Controlling CSI Reporting In A LTE Cellular Communication Network

• US 20120092989A1
• Filed: 04/09/2010
• Published: 04/19/2012
• Est. Priority Date: 06/30/2009
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Baldemair, Robert, Hagerman, Bo, Jöngren, George
• Granted Patent: US 8,929,235 B2
• Time in Patent Office: Days
• US Class Current: 370/230
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 72/1268 of uplink data flows

Abstract

The object of the present invention is to distribute the transmission of the CSI (Channel state information) reports among the different UEs, wherein the CSI reports are based on measurements on cell specific reference signals from the base station. This is achieved in a LTE cellular communication network by controlling the transmission of CSI reports from the UEs.

Claims

1. A method in a base station in a Long Term Evolution, LTE, cellular communication network for controlling Channel State Information, CSI, reports to be sent by a User Equipment, UE, wherein the CSI reports are based on measurements on cell specific reference signals from the base station, the method comprising:

determining an interval/pattern with which the cell specific reference signals should be sent from the base station, and

determining a parameter dependent on the interval/pattern which is indicative of when the UE should send CSI reports to distribute CSI reports from different UEs.

2. The method according to claim 1, further comprising:

sending the parameter to the UE.

3. The method according to claim 1, wherein the parameter is a transmission pattern indicative of UE transmission of CSI reports.

4. The method according to claim 2, further comprising:

sending a command to the UE to transmit a CSI report wherein the parameter is a time delay defined from reception at the UE of the command to send the CSI report to the transmission of the CSI report.

5. The method according to claim 1, wherein the parameter is a UE-specific parameter known both at the base station and at the UE.

6. The method according to claim 5, wherein the UE-specific parameter is a cell radio network temporary identifier, C-RNTI.

7. A method in a User Equipment, UE, in a Long Term Evolution, LTE, cellular communication network for sending Channel State Information, CSI, reports, wherein the CSI reports are based on measurements on cell specific reference signals from a base station, and the cell specific reference signals are sent with a predefined interval/pattern, the method comprising:

using a parameter, wherein the parameter is dependent on the interval/pattern and is indicative of when the UE should send CSI reports, and

sending the CSI reports according to the parameter.

8. The method according to claim 7, wherein the parameter is received from the base station.

9. The method according to claim 7, wherein the parameter is a transmission pattern for UE transmission of CSI reports.

10. The method according to claim 8, further comprising:

receiving a command to transmit a CSI report wherein the parameter is a time delay defined from reception at the UE of the command to send the CSI report to the transmission of the CSI report.

11. The method according to claim 7, wherein the parameter is a UE-specific parameter known both at the base station and at the UE.

12. The method according to claim 8, wherein the UE specific parameter is a cell radio network temporary identifier, C-RNTI.

13. A base station adapted for a Long Term Evolution, LTE, cellular communication network for controlling Channel State Information, CSI, reports to be sent by a User Equipment, UE, wherein the CSI reports are based on measurements on cell specific reference signals from the base station, the base station comprising:

a first processing unit configured to determine an interval/pattern with which the cell specific reference signals should be sent from the base station, and

a second processing unit configured to determine a parameter dependent on the interval/pattern which is indicative of when the UE should send CSI reports to distribute CSI reports from different UEs.

14. The base station according to claim 13, further comprising:

a transmitter configured to send the parameter to the UE.

15. The base station according to claim 13, wherein the parameter is a transmission pattern indicative of UE transmission of CSI reports.

16. The base station according to claim 14, wherein the transmitter is further configured to send a command to the UE to transmit a CSI report wherein the parameter is a time delay defined from reception at the UE of the command to send the CSI report to the transmission of the CSI report.

17. The base station according to claim 13, wherein the parameter is a UE-specific parameter known both at the base station and at the UE.

18. The base station according to claim 17, wherein the UE-specific parameter is a cell radio network temporary identifier, C-RNTI.

19. A User Equipment, UE, adapted for a Long Term Evolution, LTE, cellular communication network for sending Channel State Information, CSI, reports, wherein the CSI reports are based on measurements on cell specific reference signals from a base station, and the cell specific reference signals are sent with a predefined interval/pattern, the UE comprising:

a CSI reporting manager configured to use a parameter, wherein the parameter is dependent on the interval/pattern and is indicative of when the UE should send CSI reports, and

a transmitter configured to send the CSI reports according to the parameter.

20. The UE according to claim 19, further comprising:

a receiver configured to receive the parameter from the base station.

21. The UE according to claim 19, wherein the parameter is a transmission pattern for UE transmission of CSI reports.

22. The UE according to claim 20, wherein the receiver is further configured to receive a command to transmit a CSI report wherein the parameter is a time delay defined from reception at the UE of the command to send the CSI report to the transmission of the CSI report.

23. The UE according to claim 19, wherein the parameter is a UE-specific parameter known both at the base station and at the UE.

24. The UE according to claim 23, wherein the UE specific parameter is a cell radio network temporary identifier, C-RNTI.