CSI AND ACK REPORTING ENHANCEMENTS IN LTE/LTE-A WITH UNLICENSED SPECTRUM

• US 20150055588A1
• Filed: 08/20/2014
• Published: 02/26/2015
• 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
• Granted Patent: US 10,034,283 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• 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:

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

across subframes;

between slots within subframes;

or

across different symbols and tones in each resource block; and

transmitting, by the base station, the radio frame to a user equipment (UE).

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 CSI-RS or IMR resources.

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, further including:

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.

5. 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 stagger within a radio frame, by a base station, at least one of Channel State Information Reference Signal (CSI-RS) resources or Interference Measurement Resource (IMR) resources at least one of;

across subframes;

between slots within subframes;

or

across different symbols and tones in each resource block; and

to transmit, by the base station, the radio frame to a user equipment (UE).

6. The apparatus of claim 5, 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 CSI-RS or IMR resources.

7. The apparatus of claim 6, 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.

8. The apparatus of claim 5, further including configuration of the at least one processor 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.

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

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

across subframes;

between slots within subframes;

or

across different symbols and tones in each resource block; and

code for causing the one or more computers to transmit, by the base station, the radio frame to a user equipment (UE).

10. The non-transitory computer-readable medium of claim 9, 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 CSI-RS or IMR resources.

11. The non-transitory computer-readable medium of claim 10, 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.

12. The non-transitory computer-readable medium of claim 9, further including:

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.

13. A method of wireless communication, comprising:

receiving, by a user equipment (UE), a radio frame from a base station, wherein the radio frame has at least one of Channel State Information Reference Signal (CSI-RS) or Interference Measurement Resource (IMR) resources staggered at least one of;

across subframes;

between slots within subframes;

or

within a plurality of symbols across a slot for different resource blocks; and

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

14. The method of claim 13, further including:

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

15. The method of claim 14, further including:

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