CSI and ACK reporting enhancements in LTE/LTE-A with unlicensed spectrum

• US 10,034,283 B2
• Filed: 08/20/2014
• Issued: 07/24/2018
• Est. Priority Date: 08/23/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Yerramalli, Srinivas, Luo, Tao, Chen, Wanshi, Bhushan, Naga
• Primary Examiner(s): TRAN, PHUC H
• Application Number:
  US14/464,409
• Publication Number:
  US 20150055588A1
• Time in Patent Office: 1,434 Days
• CPC Class Codes: H04L 1/00 Arrangements for detecting or preventing errors in the information received correcting synchronisation H04L7/00
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04L 5/0073 Allocation arrangements that take into account other cell interferences for intercell interference mitigation or co-ordination in orthogonal multiplex systems H04J11/005
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames

Abstract

Channel state information (CSI) and acknowledgement (ACK) reporting enhancements in Long Term Evolution (LTE)/LTE-Advanced (LTE-A) enabling communications over an unlicensed spectrum are disclosed. For example, ACK/NAK may include unlicensed spectrum interference information, such as WIFI interference. Additionally, in anticipation of a future downlink transmission, UEs may report WiFI interference to base stations absent a current downlink transmission. Also, CSI-RS and/or IMR resources may be staggered across subframes and/or within slots of subframes. Further, CSI reporting may include separate reports for CSI-RS resources that experience unlicensed spectrum interference and interference free CSI-RS resources. Still further, CSI reports may include a request to the base station to switch the current channel or band. Finally, inter-RAT ACK and CSI reporting may be provided on a second unlicensed spectrum band, such as a WIFI band, for a first unlicensed spectrum band, such as an LTE/LTE-A unlicensed band.

Claims

1. A method of wireless communication, comprising:

generating, by a base station, at least one of Channel State Information Reference Signal (CSI-RS) or Interference Measurement Resource (IMR); and

transmitting the CSI-RS or the IMR in a radio frame to a user equipment (UE), wherein the transmitting of the CSI-RS or the IMR includes transmitting the CSI-RS or the IMR on resources located in different resource blocks in terms of frequency, wherein the resources on which the CSI-RS or the IMR is transmitted are staggered within the radio frame between slots within a subframe.

2. The method of claim 1, further including:

receiving, by the base station, a channel state report form the UE, wherein the channel state report is based on the staggered at least one of the resources on which the CSI-RS or the IMR is transmitted.

3. The method of claim 2, further including:

determining one or more resources for use by the UE based on the received channel state report.

4. The method of claim 1, wherein the resources on which the CSI-RS or the IMR is transmitted are further staggered across different symbols and tones in each resource block.

5. A method of wireless communication, comprising:

generating, by a base station, at least one of Channel State Information Reference Signal (CSI-RS) or Interference Measurement Resource (IMR);

indicating, by the base station, to other base stations at least one of;

a resource staggering pattern;

an IMR resource configuration; and

a null tone configuration; and

transmitting the CSI-RS or the IMR in a radio frame to a user equipment (UE), wherein the transmitting of the CSI-RS or the IMR includes transmitting the CSI-RS or the IMR on resources located in different resource blocks in terms of frequency, wherein the resources on which the CSI-RS or the IMR is transmitted are staggered within the radio frame at least one of;

between slots within a subframe;

or

across different symbols and tones in each resource block.

6. The method of claim 5, wherein the indicating includes indicating, by the base station, to other base stations the resource staggering pattern.

7. The method of claim 5, wherein the indicating includes indicating, by the base station, to other base stations the IMR resource configuration.

8. The method of claim 5, wherein the indicating includes indicating, by the base station, to other base stations the null tone configuration.

9. 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 generate, by a base station, at least one of Channel State Information Reference Signal (CSI-RS) or Interference Measurement Resource (IMR); and

to transmit the CSI-RS or the IMR in a radio frame to a user equipment (UE), wherein the configuration to transmit includes configuration to transmit the CSI-RS or the IMR on resources located in different resource blocks in terms of frequency, wherein the resources on which the CSI-RS or the IMR is transmitted are staggered within the radio frame between slots within a subframe.

10. The apparatus of claim 9, further including configuration of the at least one processor to receive, by the base station, a channel state report form the UE, wherein the channel state report is based on the staggered at least one of the resources on which the CSI-RS or the IMR is transmitted.

11. The apparatus of claim 10, further including configuration of the at least one processor to determine one or more resources for use by the UE based on the received channel state report.

12. 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 generate, by a base station, at least one of Channel State Information Reference Signal (CSI-RS) or Interference Measurement Resource (IMR);

to indicate, by the base station, to other base stations at least one of;

a resource staggering pattern;

an IMR resource configuration; and

a null tone configuration; and

to transmit the CSI-RS or the IMR in a radio frame to a user equipment (UE), wherein the configuration to transmit includes configuration to transmit the CSI-RS or the IMR on resources located in different resource blocks in terms of frequency, wherein the resources on which the CSI-RS or the IMR is transmitted are staggered within the radio frame at least one of;

between slots within a subframe;

or

across different symbols and tones in each resource block.

13. A non-transitory computer-readable medium having program code recorded thereon, comprising:

code for causing one or more computers to generate, by a base station, at least one of Channel State Information Reference Signal (CSI-RS) or Interference Measurement Resource (IMR); and

code for causing one or more computers to transmit the CSI-RS or the IMR in a radio frame to a user equipment (UE), wherein the code for causing the one or more computers to transmit includes code for causing the one or more computers to transmit the CSI-RS or the IMR on resources located in different resource blocks in terms of frequency, wherein the resources on which the CSI-RS or the IMR is transmitted are staggered within the radio frame between slots within a subframe.

14. The non-transitory computer-readable medium of claim 13, further including:

code for causing the one or more computers to receive, by the base station, a channel state report form the UE, wherein the channel state report is based on the staggered at least one of the resources on which the CSI-RS or the IMR is transmitted.

15. The non-transitory computer-readable medium of claim 14, further including:

code for causing the one or more computers to determine one or more resources for use by the UE based on the received channel state report.

16. A non-transitory computer-readable medium having program code recorded thereon, comprising:

code for causing one or more computers to generate, by a base station, at least one of Channel State Information Reference Signal (CSI-RS) or Interference Measurement Resource (IMR);

code for causing the one or more computers to indicate, by the base station, to other base stations at least one of;

a resource staggering pattern;

an IMR resource configuration; and

a null tone configuration; and

code for causing one or more computers to transmit the CSI-RS or the IMR in a radio frame to a user equipment (UE), wherein the code for causing the one or more computers to transmit includes code for causing the one or more computers to transmit the CSI-RS or the IMR on resources located in different resource blocks in terms of frequency, wherein the resources on which the CSI-RS or the IMR is transmitted are staggered within the radio frame at least one of;

between slots within a subframe;

or

across different symbols and tones in each resource block.

17. A method of wireless communication, comprising:

receiving, by a user equipment (UE), at least one of Channel State Information Reference Signal (CSI-RS) or Interference Measurement Resource (IMR) in a radio frame from a base station, wherein the receiving of the CSI-RS or the IMR includes receiving the CSI-RS or the IMR on resources located in different resource blocks in terms of frequency, wherein the resources on which the CSI-RS or the IMR is received are staggered within the radio frame

between slots within a subframe; and

performing, by the UE, at least one of channel estimation or interference estimation based on the staggered at least one of the resource on which the CSI-RS or the IMR is received.

18. The method of claim 17, further including:

generating, by the UE, a channel state report based on the at least one of channel estimation or interference estimation.

19. The method of claim 18, further including:

transmitting, by the UE, the channel state report to the base station.