CSI FEEDBACK IN LTE/LTE-ADVANCED SYSTEMS WITH UNLICENSED SPECTRUM

• US 20150173056A1
• Filed: 12/09/2014
• Published: 06/18/2015
• Est. Priority Date: 12/13/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Yerramalli, Srinivas, Chen, Wanshi, Luo, Tao, Gaal, Peter, Malladi, Durga Prasad, Wei, Yongbin, Xu, Hao, Ji, Tingfang, Bhushan, Naga, Damnjanovic, Aleksandar
• Granted Patent: US 10,104,565 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04L 5/0057 Physical resource allocation for CQI
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

Channel state information (CSI) feedback in long term evolution (LTE) and LTE-Advanced (LTE-A) networks including unlicensed spectrum is disclosed in which a base station obtains clear channel assessment (CCA) result information from neighboring base stations, either directly or by determining such results from measurement or reports from user equipment (UE) served by the base station. The base station may then generate control signaling based on the CCA result information for transmission to the one or more UEs served by the base station.

Claims

1. A method of wireless communication, comprising:

obtaining, by a base station, clear channel assessment (CCA) result information for a plurality of neighboring base stations;

generating, by the base station, control signaling for one or more user equipments (UEs) served by the base station, wherein the control signaling is based, at least in part, on the CCA result information; and

transmitting the control signaling to the one or more UEs.

2. The method of claim 1, wherein the obtaining includes one or more of:

receiving, by the base station, the CCA result information via backhaul communication link to at least one of the plurality of neighboring base stations;

receiving, by the base station, the CCA result information from the one or more UEs, wherein the CCA result information is determined from measurement estimates of transmission signals indicative of the CCA result information in a measurement report of the one or more UEs over a plurality of transmission frames; and

detecting, by the base station, transmission signals indicative of the CCA result information from one or more of the plurality of neighboring base stations over the plurality of transmission frames.

3. The method of claim 1, further including:

obtaining, by the base station, hysteretic interference information based on interference detected from one or more neighboring base stations of the plurality of neighboring base stations over a plurality of transmission frames; and

identifying, by the base station, the hysteretic interference information associated with at least one neighboring base station having asynchronous operation from other neighboring base stations of the plurality of base stations, wherein the control signaling is further generated based on the hysteretic interference information associated with the at least one neighboring base station.

4. The method of claim 3, wherein the obtaining the hysteretic interference information includes:

detecting, by the base station, a failed CCA for the base station;

measuring, by the base station, the interference experienced at the base station; and

generating the hysteretic interference information based, at least in part, on the measured interference.

5. The method of claim 4, further including:

receiving UE interference information from the one or more UEs, wherein the generating the hysteretic interference information includes weighting the measured interference using one or more of;

the CCA result information and the UE interference information.

6. The method of claim 3, wherein the obtaining the hysteretic interference information includes receiving the hysteretic interference information from the one or more UEs as a part of a measurement report.

7. The method of claim 3, further including:

determining, by the base station, one or more timing offsets between the base station and the at least one neighboring base station based on the hysteretic interference information, wherein the control signaling is generated further based on the one or more timing offsets.

8. The method of claim 3, further including:

identifying, by the base station, the hysteretic interference information associated with at least one neighboring WiFi base station having WiFi transmissions, wherein the control signaling is further generated based on the hysteretic interference information associated with the at least one neighboring WiFi base station.

9. A method of wireless communication, comprising:

detecting, by a user equipment (UE), transmission signals indicative of clear channel assessment (CCA) result information for a plurality of neighboring base stations;

determining, by the UE, CCA result information estimate for the plurality of neighboring base stations based on the transmission signals indicative of CCA result information; and

transmitting, by the UE, a measurement report to a serving base station, wherein the measurement report includes the CCA result information estimate.

10. The method of claim 9, wherein the transmission signals indicative of CCA result information are detected across a plurality of transmission frames, and

wherein the CCA result information estimate is determined across the plurality of transmission frames.

11. The method of claim 9, wherein the transmission signals indicative of CCA result information include one or more of:

channel usage beacon signals (CUBS) and channel state information reference signals (CSI-RS).

12. The method of claim 9, further including:

detecting, by the UE, interference conditions from the plurality of neighboring base stations over a plurality of transmission frames;

processing the interference conditions into hysteretic interference information associated with interference at the UE from the plurality of neighboring base stations, wherein the hysteretic interference information is included in the measurement report.

13. A computer program product for wireless communications in a wireless network, comprising:

a non-transitory computer-readable medium having program code recorded thereon, the program code including;

program code for causing a computer to obtain, by a base station, clear channel assessment (CCA) result information for a plurality of neighboring base stations;

program code for causing the computer to generate, by the base station, control signaling for one or more user equipments (UEs) served by the base station, wherein the control signaling is based, at least in part, on the CCA result information; and

program code for causing the computer to transmit the control signaling to the one or more UEs.

14. The computer program product of claim 13, wherein the program code for causing the computer to obtain includes one or more of:

program code for causing the computer to receive, by the base station, the CCA result information via backhaul communication link to at least one of the plurality of neighboring base stations;

program code for causing the computer to receive, by the base station, the CCA result information from the one or more UEs, wherein the CCA result information is determined from measurement estimates of transmission signals indicative of the CCA result information in a measurement report of the one or more UEs over a plurality of transmission frames; and

program code for causing the computer to detect, by the base station, transmission signals indicative of the CCA result information from one or more of the plurality of neighboring base stations over the plurality of transmission frames.

15. The computer program product of claim 13, further including:

program code for causing the computer to obtain, by the base station, hysteretic interference information based on interference detected from one or more neighboring base stations of the plurality of neighboring base stations over a plurality of transmission frames; and

program code for causing the computer to identify, by the base station, the hysteretic interference information associated with at least one neighboring base station having asynchronous operation from other neighboring base stations of the plurality of base stations, wherein the control signaling is further generated based on the hysteretic interference information associated with the at least one neighboring base station.

16. The computer program product of claim 15, wherein the program code for causing the computer to obtain the hysteretic interference information includes:

program code for causing the computer to detect, by the base station, a failed CCA for the base station;

program code for causing the computer to measure, by the base station, the interference experienced at the base station; and

program code for causing the computer to generate the hysteretic interference information based, at least in part, on the measured interference.

17. The computer program product of claim 16, further including:

program code for causing the computer to receive UE interference information from the one or more UEs, wherein the program code for causing the computer to generate the hysteretic interference information includes program code for causing the computer to weight the measured interference using one or more of;

the CCA result information and the UE interference information.

18. The computer program product of claim 15, wherein the program code for causing the computer to obtain the hysteretic interference information includes program code for causing the computer to receive the hysteretic interference information from the one or more UEs as a part of a measurement report.

19. The computer program product of claim 15, further including:

program code for causing the computer to determine, by the base station, one or more timing offsets between the base station and the at least one neighboring base station based on the hysteretic interference information, wherein the control signaling is generated further based on the one or more timing offsets.

20. The computer program product of claim 15, further including:

program code for causing the computer to identify, by the base station, the hysteretic interference information associated with at least one neighboring WiFi base station having WiFi transmissions, wherein the control signaling is further generated based on the hysteretic interference information associated with the at least one neighboring WiFi base station.

21. An apparatus configured for wireless communication, the apparatus comprising:

at least one processor; and

a memory coupled to the at least one processor,

wherein the at least one processor is configured;

to obtain, by a base station, clear channel assessment (CCA) result information for a plurality of neighboring base stations;

to generate, by the base station, control signaling for one or more user equipments (UEs) served by the base station, wherein the control signaling is based, at least in part, on the CCA result information; and

to transmit the control signaling to the one or more UEs.

22. The apparatus of claim 21, wherein the configuration of the at least one processor to obtain includes configuration of the at least one processor to one or more of:

receive, by the base station, the CCA result information via backhaul communication link to at least one of the plurality of neighboring base stations;

receive, by the base station, the CCA result information from the one or more UEs, wherein the CCA result information is determined from measurement estimates of transmission signals indicative of the CCA result information in a measurement report of the one or more UEs over a plurality of transmission frames; and

detect, by the base station, transmission signals indicative of the CCA result information from one or more of the plurality of neighboring base stations over the plurality of transmission frames.

23. The apparatus of claim 21, further including configuration of the at least one processor:

to obtain, by the base station, hysteretic interference information based on interference detected from one or more neighboring base stations of the plurality of neighboring base stations over a plurality of transmission frames; and

to identify, by the base station, the hysteretic interference information associated with at least one neighboring base station having asynchronous operation from other neighboring base stations of the plurality of base stations, wherein the control signaling is further generated based on the hysteretic interference information associated with the at least one neighboring base station.

24. The apparatus of claim 23, wherein the configuration of the at least one processor to obtain the hysteretic interference information includes configuration of the at least one processor:

to detect, by the base station, a failed CCA for the base station;

to measure, by the base station, the interference experienced at the base station; and

to generate the hysteretic interference information based, at least in part, on the measured interference.

25. The apparatus of claim 24, further including configuration of the at least one processor to receive UE interference information from the one or more UEs, wherein the configuration of the at least one processor to generate the hysteretic interference information includes configuration to weight the measured interference using one or more of:

the CCA result information and the UE interference information.

26. The apparatus of claim 23, wherein the configuration of the at least one processor to obtain the hysteretic interference information includes configuration to receive the hysteretic interference information from the one or more UEs as a part of a measurement report.

27. The apparatus of claim 23, further including configuration of the at least one processor to determine, by the base station, one or more timing offsets between the base station and the at least one neighboring base station based on the hysteretic interference information, wherein the control signaling is generated further based on the one or more timing offsets.

28. The apparatus of claim 23, further including configuration of the at least one processor to identify, by the base station, the hysteretic interference information associated with at least one neighboring WiFi base station having WiFi transmissions, wherein the control signaling is further generated based on the hysteretic interference information associated with the at least one neighboring WiFi base station.