CSI measurement and feedback for EMTC-U system
Techniques described herein can facilitate Channel-State Information (CSI) measurement and feedback for communication in unlicensed spectrum or Sounding Reference Signal (SRS) transmission and/or channel-state estimation for communication in unlicensed spectrum. In an example, an apparatus is configured to be employed in a User Equipment (UE), and the apparatus comprises a Radio Frequency (RF) circuitry interface and processing circuitry configured to perform CSI measurement for communication in unlicensed spectrum. The apparatus further generates data for feedback according to the CSI measurement, and sends the data for feedback to RF circuitry via the RF circuitry interface. In an example, a frame structure of a data channel begins with a downlink (DL) transmission or soon after an initial signal. In an example, the CSI measurement includes measuring Channel Quality Information (CQI) for one or more sub-bands.
1. One or more non-transitory, computer-readable media comprising instructions that, when executed, cause a user equipment (UE) to:
generate a Sounding Reference Signal (SRS) for uplink (UL) channel estimation by a base station for communication in unlicensed spectrum,
wherein the communication is over a frame structure of a data dwell time comprising a downlink (DL) dwell time and a UL dwell time, wherein a DL transmission in the DL dwell time is to trigger an SRS transmission of the SRS within an available UL dwell time.
2. The one or more non-transitory, computer-readable media of claim 1 , wherein Long Term Evolution (LTE) signal generation mechanisms are reused.
3. The one or more non-transitory, computer-readable media of claim 1 , wherein the communication for the SRS is to use 6 Resource Blocks (RBs) within a data hop, and the SRS is generated to have a comb-like structure within the 6 RBs.
4. The one or more non-transitory, computer-readable media of claim 3 , wherein the SRS is to occupy all tones across the 6 RBs using different Cyclic Delay Diversity (CDD) or Orthogonal Cover Codes (OCCs).
5. The one or more non-transitory, computer-readable media of claim 1 , wherein the instructions, when executed, cause the UE to:
generate SRS transmission hopping for the SRS in a carrier-specific manner;
generate hopping patterns for the SRS transmission hopping based on a data hopping pattern; and
determine the data hopping pattern based on a function of a Physical Cell Identity (PCI) and System Frame Number (SFN)+eFrame number.
6. The one or more non-transitory, computer-readable media of claim 1 , wherein the instructions, when executed, cause the UE to perform periodic SRS transmissions with a periodicity configured through Radio Resource Control (RRC).
7. The one or more non-transitory, computer-readable media of claim 1 , wherein the frame structure of the data dwell time begins with a frequency tuning period, followed by a presence signal period, followed by a DL transmission.
8. The one or more non-transitory, computer-readable media of claim 7 , wherein the frame structure of the data dwell time is a DL-UL-DL-UL frame structure.
9. The one or more non-transitory, computer-readable media of claim 8 , wherein the DL-UL-DL-UL frame structure further includes the frequency tuning period, a Clear Channel Assignment (CCA) and enhanced CCA (eCCA) period, the presence signal period, a DL subframes period, a UL subframes period, a CCA and eCCA period, a DL subframes period and a UL subframes period in sequence.
10. The one or more non-transitory, computer-readable media of claim 1 , wherein the communication is an enhanced Machine Type Communication (eMTC).
11. A User Equipment (UE), comprising:
a radio frequency (RF) circuitry interface; and
processing circuitry coupled to the RF circuitry interface, configured to:
generate a sounding reference signal (SRS) for uplink (UL) channel estimation by a base station for communication in unlicensed spectrum,
wherein the communication is over a frame structure of a data dwell time comprising a downlink (DL) dwell time and a UL dwell time, wherein a DL transmission in the DL dwell time is to trigger an SRS transmission of the SRS within an available UL dwell time.
12. The UE of claim 11 , wherein the communication for the SRS is to use 6 Resource Blocks (RBs) within a data hop, and the SRS is generated to have a comb-like structure within the 6 RBs.
13. The UE of claim 12 , wherein the SRS is to occupy all tones across the 6 RBs using different Cyclic Delay Diversity (CDD) or Orthogonal Cover Codes (OCCs).
14. The UE of claim 11 , wherein the processing circuitry is further configured to perform periodic SRS transmissions with a periodicity configured through Radio Resource Control (RRC).
15. The UE of claim 11 , wherein the frame structure of the data dwell time begins with a frequency tuning period, followed by a presence signal period, followed by a DL transmission.
16. The UE of claim 15 , wherein the frame structure of the data dwell time is a DL-UL-DL-UL frame structure.
17. The UE of claim 16 , wherein the DL-UL-DL-UL frame structure further includes the frequency tuning period, a Clear Channel Assignment (CCA) and enhanced CCA (eCCA) period, the presence signal period, a DL subframes period, a UL subframes period, a CCA and eCCA period, a DL subframes period and a UL subframes period in sequence.
18. The UE of claim 11 , wherein the processing circuitry is further configured to:
generate SRS transmission hopping for the SRS in a carrier-specific manner;
generate hopping patterns for the SRS transmission hopping based on a data hopping pattern; and
determine the data hopping pattern based on a function of a Physical Cell Identity (PCI) and System Frame Number (SFN)+eFrame number.
19. The UE of claim 11 , wherein the communication is an enhanced Machine Type Communication (eMTC).
20. A method performed by a user equipment (UE), comprising:
generating a sounding reference signal (SRS) for uplink (UL) channel estimation by a base station for communication in unlicensed spectrum, wherein the communication is over a frame structure of a data dwell time comprising a downlink (DL) dwell time and a UL dwell time, wherein a DL transmission in the DL dwell time is to trigger an SRS transmission of the SRS within an available UL dwell time;
generating SRS transmission hopping for the SRS in a carrier-specific manner;
generating hopping patterns for the SRS transmission hopping based on a data hopping pattern; and
determining the data hopping pattern based on a function of a Physical Cell Identity (PCI) and System Frame Number (SFN)+eFrame number.