SELF-CONTAINED TRANSMISSIONS FOR MACHINE TYPE COMMUNICATIONS

• US 20180139618A1
• Filed: 11/14/2017
• Published: 05/17/2018
• Est. Priority Date: 11/16/2016
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: YERRAMALLI, Srinivas, KADOUS, Tamer, PATEL, Chirag Sureshbhai, LIU, Chih-Hao, RICO ALVARINO, Alberto
• Granted Patent: US 10,645,590 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04J 2011/0016 with FDM/FDMA and TDM/TDMA
• CPC Class Codes: H04L 1/1671 the supervisory signal being transmitted together with control information
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1896 ARQ related signaling
• CPC Class Codes: H04L 27/0006 Assessment of spectral gaps suitable for allocating digitally modulated signals, e.g. for carrier allocation in cognitive radio for spectrum sharing between different networks H04W16/14
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• 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 72/1215 for collaboration of different radio technologies
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]

Abstract

Certain aspects of the present disclosure provide techniques for transmitting and receiving self-contained transmissions for enhanced machine type communications (eMTC) in unlicensed spectrum (eMTC-U). An exemplary method includes a BS determining, based on a listen before talk (LBT) procedure, that a first portion of unlicensed radio frequency spectrum is available for a frame, transmitting, on the first portion of the unlicensed radio frequency spectrum, a control channel indicating a frame format of the frame or a grant of the first portion of the unlicensed radio frequency spectrum for the frame, and communicating with a user equipment (UE) according to the frame format or the grant during the frame.

Claims

1. A method for wireless communications by a base station (BS), comprising:

determining, based on a listen before talk (LBT) procedure, that a first portion of unlicensed radio frequency spectrum is available for a frame;

transmitting, on the first portion of the unlicensed radio frequency spectrum, a control channel indicating a frame format of the frame or a grant of the first portion of the unlicensed radio frequency spectrum for the frame; and

communicating with a user equipment (UE) according to the frame format or the grant during the frame.

2. The method of claim 1, wherein:

the control channel comprises a physical downlink control channel (PDCCH),

the grant indicates the BS will transmit a physical downlink shared channel (PDSCH) to the UE, and

the communicating with the UE comprises;

transmitting the PDSCH on the first portion of the unlicensed radio frequency spectrum during the frame, and

receiving an acknowledgment (ACK) of the PDSCH on the first portion of the unlicensed radio frequency spectrum from the UE during the frame or subsequent to the frame, depending on the frame structure.

3. The method of claim 1, wherein:

the grant indicates that the UE should transmit a physical uplink shared channel (PUSCH) to the BS, and

the communicating with the UE comprises receiving the PUSCH from the UE on the first portion of the unlicensed radio frequency spectrum during the frame or during a subsequent frame.

4. The method of claim 1, further comprising:

determining the first portion of the unlicensed radio frequency spectrum based on a frequency hopping pattern of the BS.

5. The method of claim 1, wherein the LBT procedure comprises:

attempting to receive a signal on the first portion of the unlicensed radio frequency spectrum for a first period at the beginning of the frame;

determining the signal was not received; and

transmitting a signature waveform on the first portion of the unlicensed radio frequency spectrum for a second period immediately after the first period.

6. The method of claim 1, wherein:

the frame format comprises a guaranteed downlink (DL) portion, a guaranteed uplink (UL) portion, and a flexible portion, and

the control channel indicates a fraction of the flexible portion will be for DL transmissions, wherein a remaining fraction of the flexible portion will be for UL transmissions.

7. The method of claim 1, further comprising:

indicating resources for at least one of a sounding reference signal (SRS) resource, a scheduling request resource, a hybrid automatic repetition request (HARQ) acknowledgment (HARQ-ACK) resource, or a channel quality indicator (CQI) reporting resource in the control channel; and

receiving at least one of an SRS via the SRS resource, a scheduling request via the scheduling request resource, a HARQ-ACK via the HARQ-ACK resource, or a CQI report via the CQI reporting resource during the frame.

8. The method of claim 1, wherein the control channel comprises a first physical downlink control channel (PDCCH) the grant indicates the BS will transmit a first physical downlink shared channel (PDSCH) to the UE, and the method further comprises:

indicating resources for a physical random access channel (PRACH) message in the first PDCCH; and

receiving a first PRACH message from the UE on the indicated resources during the frame.

9. The method of claim 1, wherein the control channel comprises a first physical downlink control channel (PDCCH) the grant indicates the BS will transmit a first physical downlink shared channel (PDSCH) to the UE, and the method further comprises:

receiving a first PRACH message from the UE during the frame;

transmitting, on the first portion or the second portion of the unlicensed radio frequency spectrum, a second PDCCH allocating resources for a second PDSCH during a second frame subsequent to the first frame; and

transmitting, on the first portion or the second portion of the unlicensed radio frequency spectrum, the second PDSCH during the second frame, wherein the second PDSCH comprises a second PRACH message responsive to the first PRACH message.

10. The method of claim 9, further comprising:

determining, based on a second listen before talk (LBT) procedure, that the first portion or a second portion of unlicensed radio frequency spectrum is available for the second frame.

11. The method of claim 10, further comprising:

receiving a third PRACH message from the UE;

determining, based on a third listen before talk (LBT) procedure, that the first portion, the second portion, or a third portion of unlicensed radio frequency spectrum is available for a third frame subsequent to the second frame;

transmitting, on the first portion, the second portion, or the third portion of the unlicensed radio frequency spectrum, a third PDCCH allocating resources for a third PDSCH during the third frame; and

transmitting, on the first portion, the second portion, or the third portion of the unlicensed radio frequency spectrum, the third PDSCH during the third frame, wherein the third PDSCH comprises a fourth PRACH message responsive to the third PRACH message.

12. The method of claim 1, further comprising:

transmitting at least one reference signal on the first portion of the unlicensed radio frequency spectrum during the frame.

13. The method of claim 1, further comprising:

transmitting an indication of a frequency hopping pattern of a cell neighboring the BS.

14. A method for wireless communications by a user equipment (UE), comprising:

detecting a signature waveform on a first portion of unlicensed radio frequency spectrum for a first period during a frame;

receiving, on the first portion of the unlicensed radio frequency spectrum and during a second period subsequent to the first period, a control channel indicating a frame format of the frame or a grant of the first portion of the unlicensed radio frequency spectrum for the frame; and

communicating with a base station (BS) according to the frame format or the grant during the frame.

15. The method of claim 14, wherein:

the control channel comprises a physical downlink control channel (PDCCH),

the grant indicates the BS will transmit a physical downlink shared channel (PDSCH) to the UE, and

the communicating with the BS comprises;

receiving the PDSCH on the first portion of the unlicensed radio frequency spectrum during the frame, and

transmitting an acknowledgment (ACK) of the PDSCH on the first portion of the unlicensed radio frequency spectrum during the frame or subsequent to the frame, depending on the frame structure.

16. The method of claim 14, wherein:

the grant indicates that the UE should transmit a physical uplink shared channel (PUSCH) to the BS, and

the communicating with the BS comprises transmitting the PUSCH to the BS on the first portion of the unlicensed radio frequency spectrum during the frame or during a subsequent frame.

17. The method of claim 14, further comprising:

determining the first portion of the unlicensed radio frequency spectrum based on a frequency hopping pattern of the BS.

18. The method of claim 14, wherein:

the frame format comprises a guaranteed downlink (DL) portion, a guaranteed uplink (UL) portion, and a flexible portion, and the method further comprises;

determining, based on the control channel, that the flexible portion will be for DL transmissions or for UL transmissions.

20. The method of claim 14, further comprising:

determining, based on the control channel, at least one of a sounding reference signal (SRS) resource, a scheduling request resource, a hybrid automatic repetition request (HARQ) acknowledgment (HARQ-ACK) resource, or a channel quality indicator (CQI) reporting resource; and

transmitting at least one of an SRS via the SRS resource, a scheduling request via the SRS resource, a HARQ-ACK via the HARQ-ACK resource, or a CQI report via the CQI reporting resource during the frame.

21. The method of claim 14, wherein the control channel comprises a first physical downlink control channel (PDCCH) the grant indicates the BS will transmit a physical downlink shared channel (PDSCH) to the UE, and the method further comprises:

determining, based on the first PDCCH, resources for a physical random access channel (PRACH) message; and

transmitting a first PRACH message on the indicated resources during the frame.

22. The method of claim 14, wherein the control channel comprises a first physical downlink control channel (PDCCH), the grant indicates the BS will transmit a physical downlink shared channel (PDSCH) to the UE, and the method further comprises:

transmitting a first PRACH message during the frame;

receiving, on the first portion or the second portion of the unlicensed radio frequency spectrum, a second PDCCH allocating resources for a second PDSCH during a second frame;

receiving, on the first portion or the second portion of the unlicensed radio frequency spectrum, the second PDSCH during the second frame, wherein the second PDSCH comprises a second PRACH message responsive to the first PRACH message; and

transmitting a third PRACH message.

23. The method of claim 22, further comprising:

receiving, on the first portion, the second portion, or the third portion of the unlicensed radio frequency spectrum, a third PDCCH allocating resources for a third PDSCH during a third frame; and

receiving, on the first portion, the second portion, or the third portion of the unlicensed radio frequency spectrum, the third PDSCH during the third frame, wherein the third PDSCH comprises a fourth PRACH message responsive to the third PRACH message.

24. The method of claim 14, further comprising:

detecting at least one reference signal on the first portion of the unlicensed radio frequency spectrum during the frame; and

processing the at least one reference signal.

25. The method of claim 14, further comprising:

determining, based on an indication received from the BS, a frequency hopping pattern of a cell neighboring the BS;

determining the first portion or a second portion of unlicensed radio frequency spectrum based on the frequency hopping pattern of the cell neighboring the BS; and

detecting a signature waveform transmitted by the cell neighboring the BS on the determined first portion or second portion of unlicensed radio frequency spectrum during another frame.

26. An apparatus for wireless communications, comprising:

a processor configured to;

determine, based on a listen before talk (LBT) procedure, that a first portion of unlicensed radio frequency spectrum is available for a frame;

transmit, on the first portion of the unlicensed radio frequency spectrum, a control channel indicating a frame format of the frame or a grant of the first portion of the unlicensed radio frequency spectrum for the frame; and

communicate with a user equipment (UE) according to the frame format or the grant during the frame; and

a memory coupled with the processor.

27. An apparatus for wireless communications, comprising:

a processor configured to;

detect a signature waveform on a first portion of unlicensed radio frequency spectrum for a first period during a frame;

receive, on the first portion of the unlicensed radio frequency spectrum and during a second period subsequent to the first period, a control channel indicating a frame format of the frame or a grant of the first portion of the unlicensed radio frequency spectrum for the frame; and

communicate with a base station (BS) according to the frame format or the grant during the frame; and

a memory coupled with the processor.

28. The apparatus of claim 27, wherein:

the control channel comprises a physical downlink control channel (PDCCH),

the grant indicates the BS will transmit a physical downlink shared channel (PDSCH) to the apparatus, and

the processor is configured to communicate with the BS by;

receiving the PDSCH on the first portion of the unlicensed radio frequency spectrum during the frame, and

transmitting an acknowledgment (ACK) of the PDSCH on the first portion of the unlicensed radio frequency spectrum during the frame or during a subsequent frame, depending on the frame structure.

29. The apparatus of claim 27, wherein:

the grant indicates that the apparatus should transmit a physical uplink shared channel (PUSCH) to the BS, and

the processor is configured to communicate with the BS by transmitting the PUSCH to the BS on the first portion of the unlicensed radio frequency spectrum during the frame or a subsequent frame.

30. The apparatus of claim 27, wherein the processor is further configured to:

determine the first portion of the unlicensed radio frequency spectrum based on a frequency hopping pattern of the BS.