CSI reporting for LTE-TDD eIMTA

Patent metadata

Field	Value
Publication number	US-10341896-B2
Application number	US-201715831056-A
Country	US
Kind code	B2
Filing date	Dec 4, 2017
Priority date	Sep 27, 2013
Publication date	Jul 2, 2019
Grant date	Jul 2, 2019

Abstract

Methods, systems, and devices are described for providing periodic CSI reports and/or aperiodic CSI reports to provide CSI for both anchor and non-anchor TDD subframes in eIMTA. Periodic CSI reports may be provided based on a reference configuration, and aperiodic CSI reports may be provided based on a time of reception of a CSI request and a reference configuration. A UE may determine to report anchor or non-anchor CSI through explicit or implicit signaling. Aperiodic CSI may be used for transmission of anchor subframe CSI reports and periodic CSI may be used for transmission of non-anchor subframe CSI reports, or aperiodic CSI may be used for transmission of non-anchor subframe CSI reports and periodic CSI may be used for transmission of anchor subframe CSI reports. A determination of the reference subframe for aperiodic CSI estimation may be based on a time of receipt of an aperiodic CSI request.

First claim

What is claimed is:

1. A method of wireless communication performed by a user equipment (UE) in time-division duplex (TDD) communication with a base station, the method comprising:
receiving a channel state information (CSI) request from the base station;
determining, based at least in part on receiving the CSI request, that CSI is to be estimated for a reference TDD subframe corresponding to a first set of subframes of a TDD frame configuration, or a reference TDD subframe corresponding to a second set of subframes of the TDD frame configuration, or a combination thereof;
estimating CSI based at least in part on the determining, wherein the estimating CSI comprises estimating a first type of CSI for the reference TDD subframe corresponding to the first set of subframes of the TDD frame configuration, or estimating a second type of CSI for the reference TDD subframe corresponding to the second set of subframes of the TDD frame configuration, or a combination thereof; and
transmitting at least a portion of the estimated CSI in an identified uplink subframe, the identified uplink subframe determined based at least in part on a time of receipt of the CSI request.

2. The method of claim 1 , wherein the identified uplink subframe is determined based on a reference TDD UL/DL configuration that is different than a current configured TDD UL/DL configuration of the UE.

3. The method of claim 1 , wherein the transmitting comprises:
transmitting both estimated CSI of the first type of CSI and estimated CSI of the second type of CSI in aperiodic CSI reports.

4. The method of claim 1 , wherein the transmitting comprises:
transmitting estimated CSI of the first type of CSI in a periodic CSI report; and
transmitting estimated CSI of the second type of CSI in an aperiodic CSI report.

5. The method of claim 4 , wherein the periodic CSI report is transmitted in a fixed uplink subframe determined by a reference TDD UL/DL configuration.

6. The method of claim 5 , wherein the reference TDD UL/DL configuration is received via Layer 1 (L1) signaling, Medium Access Control (MAC) signaling, or Radio Resource Control (RRC) signaling.

7. The method of claim 5 , further comprising:
determining that an uplink subframe for reporting the periodic CSI report and the aperiodic CSI report correspond to the same uplink subframe; and
multiplexing the periodic CSI report and the aperiodic CSI report in the same uplink subframe.

8. The method of claim 5 , further comprising:
determining that an uplink subframe for reporting the periodic CSI report and the aperiodic CSI report correspond to the same uplink subframe; and
transmitting the aperiodic CSI report in the same uplink subframe.

9. The method of claim 4 , wherein the reference TDD subframe is determined based on a downlink trigger subframe containing the CSI request and a closest subsequent downlink subframe corresponding to the second set of subframes of the TDD frame configuration that is at least k subframes after the downlink trigger subframe.

10. The method of claim 9 , wherein k is greater than or equal to zero.

11. The method of claim 1 , further comprising:
receiving signaling from the base station indicating that the CSI of the first type of CSI or the CSI of the second type of CSI is to be transmitted.

12. The method of claim 11 , wherein receiving the signaling comprises:
receiving Layer 1 (L1) signaling, receiving Medium Access Control (MAC) signaling, or receiving Radio Resource Control (RRC) signaling, or a combination thereof.

13. The method of claim 11 , wherein the signaling comprises an enhanced Interference Management and Traffic Adaptation (eIMTA) CSI type field received via L1 signaling.

14. The method of claim 11 , wherein the signaling comprises a two-bit CSI request field received in a downlink control information (DCI) transmission.

15. The method of claim 1 , wherein the determining that CSI is to be estimated for a reference TDD subframe corresponding to the first set of subframes of the TDD frame configuration, or a reference TDD subframe corresponding to the second set of subframes of the TDD frame configuration, or a combination thereof, is based on a current frame index.

16. The method of claim 15 , wherein estimated CSI of the first type of CSI and estimated CSI of the second type of CSI are reported in alternating frames.

17. The method of claim 1 , wherein the identified uplink subframe is determined based on a reference TDD uplink/downlink (UL/DL) configuration.

18. The method of claim 17 , wherein the identified uplink subframe is determined based on a downlink trigger subframe containing the CSI request and closest subsequent uplink subframe corresponding to the second set of subframes of the TDD frame configuration that is at least k subframes after the downlink trigger subframe.

19. The method of claim 18 , wherein k is greater than or equal to zero.

20. An apparatus for wireless communication at a user equipment (UE) in time-division duplex (TDD) communication with a base station, the apparatus comprising:
a processor;
memory in electronic communication with the processor; and
instructions stored in the memory and executable by the processor to cause the apparatus to:
receive a channel state information (CSI) request from the base station;
determine, based at least in part on receiving the CSI request, that CSI is to be estimated for a reference TDD subframe corresponding to a first set of subframes of a TDD frame configuration, or a reference TDD subframe corresponding to a second set of subframes of the TDD frame configuration, or a combination thereof;
estimate CSI based at least in part on the determining, wherein the estimating CSI comprises estimating a first type of CSI for the reference TDD subframe corresponding to the first set of subframes of the TDD frame configuration, or estimating a second type of CSI for the reference TDD subframe corresponding to the second set of subframes of the TDD frame configuration, or a combination thereof; and
transmit at least a portion of the estimated CSI in an identified uplink subframe, the identified uplink subframe determined based at least in part on a time of receipt of the CSI request.

21. The apparatus of claim 20 , wherein the instructions to transmit are executable by the processor to cause the apparatus to:
transmit both estimated CSI of the first type of CSI and estimated CSI of the second type of CSI in aperiodic CSI reports.

22. The apparatus of claim 20 , wherein the instructions to transmit are executable by the processor to cause the apparatus to:
transmit estimated CSI of the first type of CSI in a periodic CSI report; and
transmit estimated CSI of the second type of CSI in an aperiodic CSI report.

23. The apparatus of claim 22 , wherein the reference TDD subframe is determined based on a downlink trigger subframe containing the CSI request and a closest subsequent downlink subframe corresponding to the second set of subframes of the TDD frame configuration that is at least k subframes after the downlink trigger subframe.

24. The apparatus of claim 20 , wherein the instructions are further executable by the processor to cause the apparatus to:
receive signaling from the base station indicating that the CSI of the first type of CSI or the CSI of the second type of CSI is to be transmitted.

25. The apparatus of claim 24 , wherein the instructions to receive signali

Assignees

• Qualcomm Inc

Inventors

• Cheng Peng
• Wang Neng
• Wei Chao
• Chen Wanshi
• Gaal Peter
• Xu Hao
• Hou Jilei

Classifications

• H04W72/23

  in the downlink direction of a wireless link, i.e. towards a terminal · CPC title

• H04W72/21

  in the uplink direction of a wireless link, i.e. towards the network · CPC title

• H04L1/0026

  Transmission of channel quality indication · CPC title

• H04L5/1469

  using time-sharing · CPC title

• H04L5/14

  Two-way operation using the same type of signal, i.e. duplex · CPC title