CHANNEL STATE INFORMATION MEASUREMENTS FOR LICENSE-ASSISTED ACCESS

• US 20150365152A1
• Filed: 06/12/2015
• Published: 12/17/2015
• Est. Priority Date: 06/16/2014
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Frenne, Mattias, Cheng, Jung-Fu, Falahati, Sorour, Koorapaty, Havish, Larsson, Daniel
• Granted Patent: US 10,063,304 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G03G 15/0806 on a donor element, e.g. belt, roller complete developer unit G03G15/0896
• CPC Class Codes: G03G 15/0812 characterised by the developer regulating means, e.g. structure of doctor blade
• CPC Class Codes: G03G 15/0865 Arrangements for supplying new developer
• CPC Class Codes: G03G 15/0921 Details concerning the magnetic brush roller structure, e.g. magnet configuration
• CPC Class Codes: G03G 15/0935 relating to bearings or driving mechanism
• CPC Class Codes: G03G 21/1676 for the developer unit
• CPC Class Codes: G03G 21/1814 Details of parts of process cartridge, e.g. for charging, transfer, cleaning, developing G03G21/1835 takes precedence
• CPC Class Codes: G03G 2215/0855 Materials and manufacturing of the developing device
• CPC Class Codes: G03G 2215/0872 Housing of developing device
• CPC Class Codes: G03G 2221/1654 Locks and means for positioning or alignment
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04L 27/0006 Assessment of spectral gaps suitable for allocating digitally modulated signals, e.g. for carrier allocation in cognitive radio for spectrum sharing between different networks H04W16/14
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 76/15 Setup of multiple wireless link connections

Abstract

Systems and methods relating to accurate Channel State Information (CSI) measurements for a License Assisted Secondary Cell (LA SCell) are disclosed herein. In some embodiments, a wireless device enabled to operate in a cellular communications network according to a carrier aggregation scheme using both a licensed frequency band and an unlicensed frequency band operates to determine whether a Channel State Information Reference Symbol (CSI-RS) transmission from a LA SCell of the wireless device is present in a subframe, where the LA SCell is in an unlicensed frequency band. The wireless device further operates to process a CSI-RS measurement for the LA SCell for the subframe upon determining that a CSI-RS transmission from the LA SCell is present in the subframe and refrain from processing a CSI-RS measurement for the LA SCell for the subframe upon determining that a CSI-RS transmission from the LA SCell is not present in the subframe.

Claims

1. A wireless device enabled to operate in a cellular communications network according to a carrier aggregation scheme using both a licensed frequency band and an unlicensed frequency band, comprising:

a transceiver;

at least one processor; and

memory containing instructions executable by the at least one processor whereby the wireless device operates to;

determine whether a Channel State Information Reference Symbol, CSI-RS, transmission from a License Assisted Secondary Cell, LA SCell, of the wireless device is present in a subframe, the LA SCell being in an unlicensed frequency band;

process a CSI-RS measurement for the LA SCell for the subframe upon determining that a CSI-RS transmission from the LA SCell is present in the subframe; and

refrain from processing a CSI-RS measurement for the LA SCell for the subframe upon determining that a CSI-RS transmission from the LA SCell is not present in the subframe.

2. The wireless device of claim 1 wherein, in order to determine whether a CSI-RS transmission from the LA SCell of the wireless device is present in the subframe, the wireless device further operates to:

determine whether the wireless device has received a downlink scheduling grant for the LA SCell for the subframe, wherein determining that a downlink scheduling grant has been received for the LA SCell for the subframe indicates that a CSI-RS transmission is present in the subframe.

3. The wireless device of claim 1 wherein, in order to determine whether a CSI-RS transmission from the LA SCell of the wireless device is present in the subframe, the wireless device further operates to:

determine whether the subframe is a discovery subframe for the LA SCell, wherein determining that the subframe is a discovery subframe for the LA SCell indicates that a CSI-RS transmission is present in the subframe.

4. The wireless device of claim 1 wherein, in order to determine whether a CSI-RS transmission from the LA SCell of the wireless device is present in the subframe, the wireless device further operates to:

determine whether a Downlink Control Information, DCI, message received by the wireless device includes an indication that a CSI-RS transmission is present in the subframe.

5. The wireless device of claim 1 wherein, in order to determine whether a CSI-RS transmission from the LA SCell of the wireless device is present in the subframe, the wireless device further operates to:

determine whether the wireless device has received an uplink grant for the LA SCell for the subframe, wherein determining that the wireless device has received an uplink grant for the LA SCell for the subframe indicates that a CSI-RS transmission is not present in the subframe.

6. The wireless device of claim 1 wherein, via execution of the instructions by the at least one processor, the wireless device further operates to:

upon determining that transmission from the LA SCell is present in the subframe, perform a first type of interference measurement on configured Channel State Information Interference Measurement, CSI-IM, resources in the subframe; and

otherwise, perform a second type of interference measurement on the configured CSI-IM resources in the subframe.

7. The wireless device of claim 6 wherein, via execution of the instructions by the at least one processor, the wireless device further operates to:

send a Channel State Information, CSI, report to a network node of the cellular communications network based on a latest available CSI-RS measurement for the LA SCell and the first type of interference measurement upon determining that a transmission from the LA SCell is present in the subframe; and

otherwise, send a CSI report to the network node of the cellular communications network based on the latest available CSI-RS measurement for the LA SCell and the second type of interference measurement.

8. The wireless device of claim 1 wherein, via execution of the instructions by the at least one processor, the wireless device further operates to:

determine whether a latest available valid CSI-RS measurement for the LA SCell is older than a predefined age threshold;

upon determining that the latest available valid CSI-RS measurement for the LA SCell is older than the predefined age threshold, send an indication to a network node of the cellular communications network that the latest available valid CSI-RS measurement is older than the predefined age threshold; and

upon determining that the latest available valid CSI-RS measurement for the LA SCell is not older than the predefined age threshold;

send a Channel State Information, CSI, report to the network node of the cellular communications network based on the latest available valid CSI-RS measurement for the LA SCell and the first type of interference measurement upon determining that the latest available valid CSI-RS measurement for the LA SCell is made in the same subframe from which the first type of interference measurement; and

otherwise, send a CSI report to the network node of the cellular communications network based on the latest available valid CSI-RS measurement for the LA SCell and the second type of interference measurement.

9. The wireless device of claim 1 wherein, via execution of the instructions by the at least one processor, the wireless device further operates to:

send a Channel State Information, CSI, report to a network node of the cellular communications network.

10. A method of operation of a wireless device enabled to operate in a cellular communications network according to a carrier aggregation scheme using both a licensed frequency band and an unlicensed frequency band, comprising:

determining whether a Channel State Information Reference Symbol, CSI-RS, transmission from a License Assisted Secondary Cell, LA SCell, of the wireless device is present in a subframe, the LA SCell being in an unlicensed frequency band;

processing a CSI-RS measurement for the LA SCell for the subframe upon determining that a CSI-RS transmission from the LA SCell is present in the subframe; and

refraining from processing a CSI-RS measurement for the LA SCell for the subframe upon determining that a CSI-RS transmission from the LA SCell is not present in subframe.

11. The method of claim 10 wherein determining whether a CSI-RS transmission from the LA SCell of the wireless device is present in the subframe comprises:

determining whether the wireless device has received a downlink scheduling grant for the LA SCell for the subframe, wherein determining that a downlink scheduling grant has been received for the LA SCell for the subframe indicates that a CSI-RS transmission is present in the subframe.

12. The method of claim 10 wherein determining whether a CSI-RS transmission from the LA SCell of the wireless device is present in the subframe comprises:

determining whether the subframe is a discovery subframe for the LA SCell, wherein determining that the subframe is a discovery subframe for the LA SCell indicates that a CSI-RS transmission is present in the subframe.

13. The method of claim 10 wherein determining whether a CSI-RS transmission from the LA SCell of the wireless device is present in the subframe comprises:

determining whether a Downlink Control Information, DCI, message received by the wireless device includes an indication that a CSI-RS transmission is present in the subframe.

14. The method of claim 10 wherein determining whether a CSI-RS transmission from the LA SCell of the wireless device is present in the subframe comprises:

determining whether the wireless device has received an uplink grant for the LA SCell for the subframe, wherein determining that the wireless device has received an uplink grant for the LA SCell for the subframe indicates that a CSI-RS transmission is not present in the subframe.

15. The method of claim 10 further comprising:

upon determining that transmission from the LA SCell is present in the subframe, performing a first type of interference measurement on configured Channel State Information Interference Measurement, CSI-IM, resources in the subframe; and

otherwise performing a second type of interference measurement on the configured CSI-IM resources in the subframe.

16. The method of claim 15 further comprising:

sending a Channel State Information, CSI, report to a network node of the cellular communications network based on a latest available CSI-RS measurement for the LA SCell and the first type of interference measurement upon determining that transmission from the LA SCell is present in the subframe; and

otherwise, sending a CSI report to the network node of the cellular communications network based on the latest available CSI-RS measurement for the LA SCell and the second type of interference measurement.

17. The method of claim 15 further comprising:

determining whether a latest available valid CSI-RS measurement for the LA SCell is older than a predefined age threshold;

upon determining that the latest available valid CSI-RS measurement for the LA SCell is older than the predefined age threshold, sending an indication to a network node of the cellular communications network that the latest available valid CSI-RS measurement is older than the predefined age threshold; and

upon determining that the latest available valid CSI-RS measurement for the LA SCell is not older than the predefined age threshold;

sending a Channel State Information, CSI, report to the network node of the cellular communications network based on the latest available valid CSI-RS measurement for the LA SCell and the first type of interference measurement upon determining that the latest available valid CSI-RS measurement for the LA SCell is made in the same subframe from which the first type of interference measurement; and

otherwise, sending a CSI report to the network node of the cellular communications network based on the latest available valid CSI-RS measurement for the LA SCell and the second type of interference measurement.

18. The method of claim 10 further comprising:

sending a Channel State Information, CSI, report to a network node of the cellular communications network.

19. A method of operation of a network node, comprising:

determining whether an License Assisted Secondary Cell, LA SCell, of a wireless device is permitted to transmit in an unlicensed frequency band in a subframe in which a Channel State Information Reference Symbol, CSI-RS, measurement is configured for the wireless device; and

upon determining that the LA SCell of the wireless device is permitted to transmit in the unlicensed frequency band in the subframe in which the CSI-RS measurement is configured for the wireless device, providing an indication to the wireless device that a CSI-RS transmission is present in the subframe.

20. The method of claim 19 wherein the indication is a downlink scheduling grant for the LA SCell.

21. The method of claim 19 wherein the indication is comprised in a Downlink Control Information, DCI, message.