AUTONOMOUS UPLINK TRANSMISSION TECHNIQUES USING SHARED RADIO FREQUENCY SPECTRUM

• US 20180227936A1
• Filed: 02/02/2018
• Published: 08/09/2018
• Est. Priority Date: 02/06/2017
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Yerramalli, Srinivas, Sadek, Ahmed Kamel, Kadous, Tamer
• Granted Patent: US 10,772,113 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0031 Multiple signaling transmission H04L1/1664, F15 take precedence
• CPC Class Codes: H04L 1/0067 Rate matching H04L1/0013 and H04L1/08 take precedence
• CPC Class Codes: H04L 1/1614 using bitmaps
• CPC Class Codes: H04L 1/1819 with retransmission of additional or different redundancy
• CPC Class Codes: H04L 1/1822 involving configuration of automatic repeat request [ARQ] with parallel processes
• CPC Class Codes: H04L 27/2662 Symbol synchronisation
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• 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 5/0078 Timing of allocation
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 72/1215 for collaboration of different radio technologies
• CPC Class Codes: H04W 72/1268 of uplink data flows
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 74/002 Transmission of channel access control information
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 74/0808 : using carrier sensing, e.g. carrier sense multiple access [CSMA]
• CPC Class Codes: H04W 74/0816 : with collision avoidance

Abstract

Techniques for autonomous uplink (AUL) transmissions are provided that allow for efficient use of shared radio frequency spectrum band resources. A user equipment (UE) may determine a duration of an AUL transmission and modify an uplink waveform or provide an indication to a base station of one or more channel resources that may be available for base station transmissions, in order to more fully utilize shared radio frequency spectrum band resources within a maximum channel occupancy time (MCOT). A base station may activate or deactivate AUL transmissions through downlink control information (DCI) transmitted to the UE. A UE and base station may exchange various other control information to provide relatively efficient autonomous uplink transmissions and use of the shared radio frequency spectrum band resources.

Claims

1. A method for wireless communication, comprising:

contending for access to a channel of a shared radio frequency spectrum band in accordance with an autonomous uplink configuration which indicates a transmission window available for autonomous uplink transmissions;

determining one or more channel access parameters based at least in part on one or more of a duration of an uplink transmission to be transmitted over the channel of the shared radio frequency spectrum band or a timing advance (TA) for the uplink transmission; and

transmitting the uplink transmission over the channel of the shared radio frequency spectrum band in accordance with the autonomous uplink configuration, wherein the uplink transmission indicates one or more of the channel access parameters.

2. The method of claim 1, wherein the determining one or more channel access parameters further comprises:

determining a maximum channel occupancy time (MCOT) for the uplink transmission; and

determining a difference between the MCOT and the duration of the uplink transmission, and wherein the difference between the MCOT and the duration of the uplink transmission is indicated in the uplink transmission.

3. The method of claim 2, wherein the difference between the MCOT and the duration of the uplink transmission is indicated in the channel access parameters as a number of subframes available for use by one or more other transmitters.

4. The method of claim 1, further comprising:

modifying a waveform of the uplink transmission based at least in part on the TA.

5. The method of claim 4, wherein the modifying the waveform comprises:

formatting data to be transmitted into the uplink transmission;

identifying a timing for starting a subsequent downlink transmission following the uplink transmission and a maximum time gap between the uplink transmission and the subsequent downlink transmission;

determining a difference between the maximum time gap and the TA; and

puncturing a last symbol of the uplink transmission for a duration of the difference between the maximum time gap and the TA.

6. The method of claim 4, wherein the modifying the waveform comprises:

formatting data to be transmitted into the uplink transmission;

identifying a timing for starting a subsequent downlink transmission following the uplink transmission and a maximum time gap between the uplink transmission and the subsequent downlink transmission;

determining a time difference between an end of a last symbol of the uplink transmission and the maximum time gap; and

cyclically extending samples of the last symbol of the uplink transmission to extend for a duration of the difference between the maximum time gap and the TA.

7. The method of claim 1, wherein the determining one or more channel access parameters further comprises:

determining that the TA exceeds a maximum time gap between the uplink transmission and a subsequent downlink transmission, and wherein the TA is indicated in the uplink transmission to allow another transmitter to transmit a reservation signal for at least a portion of the TA.

8. The method of claim 1, further comprising:

identifying uplink control information (UCI) associated with the uplink transmission; and

transmitting the UCI in a symbol of the uplink transmission before a last symbol of the uplink transmission.

9. The method of claim 1, further comprising:

identifying a time for starting a subsequent downlink transmission following the uplink transmission; and

formatting the uplink transmission to occupy the channel of the shared radio frequency spectrum band until the time for starting the subsequent downlink transmission, wherein a transmitter of the subsequent downlink transmission performs a clear channel assessment (CCA) to occupy a maximum time gap between the uplink transmission and the subsequent downlink transmission.

10. The method of claim 1, further comprising:

transmitting a time difference between a maximum channel occupancy time (MCOT) and a duration of the uplink transmission to a base station.

11. The method of claim 10, wherein the base station may transmit one or more transmissions during the time difference or one or more other transmitters are precluded from transmitting during the time difference.

12. The method of claim 1, further comprising:

determining that additional data is to be transmitted following the transmission window; and

transmitting one or more subsequent uplink transmissions after the uplink transmission outside of the transmission window when a maximum channel occupancy time (MCOT) is determined as part of the contending for access to the channel of the shared radio frequency spectrum band.

13. The method of claim 12, wherein a first subframe of a first subsequent uplink transmission of the one or more subsequent uplink transmissions includes control channel information that provides information on the one or more subsequent uplink transmissions.

14. A method for wireless communication, comprising:

receiving radio resource control (RRC) signaling including an autonomous uplink configuration for unscheduled autonomous uplink transmissions in a shared radio frequency spectrum band;

receiving downlink control information (DCI) that activates autonomous uplink transmissions;

contending for access to a channel of the shared radio frequency spectrum band in accordance with the autonomous uplink configuration; and

transmitting one or more autonomous uplink transmissions over the channel of the shared radio frequency spectrum band in accordance with the autonomous uplink configuration.

15. The method of claim 14, further comprising:

receiving subsequent DCI that deactivates autonomous uplink transmissions; and

discontinuing contending for access to the channel of the shared radio frequency spectrum band responsive to the receiving the subsequent DCI.

16. The method of claim 14, wherein the DCI comprises a cyclic redundancy check (CRC) field scrambled with an identifier.

17. The method of claim 16, wherein a value of the identifier indicates that the DCI is associated with autonomous uplink transmissions.

18. The method of claim 14, wherein the autonomous uplink configuration enables autonomous uplink transmissions on one or more transmit antennas according to a multiple input multiple output (MIMO) configuration.

19. A method for wireless communication, comprising:

identifying an autonomous uplink configuration for unscheduled uplink transmissions in a shared radio frequency spectrum band;

contending for access to a channel of the shared radio frequency spectrum band in accordance with the autonomous uplink configuration;

determining uplink control information and uplink shared channel information for an uplink transmission to be transmitted over the channel of the shared radio frequency spectrum band;

rate matching the uplink shared channel information around the uplink control information in the uplink transmission; and

transmitting the uplink transmission over the channel of the shared radio frequency spectrum band in accordance with the autonomous uplink configuration.

20. The method of claim 19, wherein resources used for the uplink control information and rate matching of the shared channel information are configured in the autonomous uplink configuration.

21. The method of claim 19, wherein a payload size of the uplink control information is a fixed size configured in the autonomous uplink configuration.

22. The method of claim 21, wherein the payload size is independent of a number of subframes of the uplink transmission.

23. The method of claim 19, wherein the uplink control information comprises one or more of a hybrid automatic repeat request (HARQ) identification, a burst length of the uplink transmission, a maximum channel occupancy time (MCOT), a redundancy version (RV) indication, a new data indicator (NDI), or a user equipment (UE) identifier.

24. The method of claim 19, wherein the uplink control information comprises a time difference between a maximum channel occupancy time (MCOT) and a duration of a burst length of the uplink transmission.

25. A method for wireless communication, comprising:

identifying an autonomous uplink configuration for unscheduled uplink transmissions in a shared radio frequency spectrum band;

receiving autonomous downlink control information (A-DCI) associated with one or more autonomous uplink transmissions; and

transmitting an autonomous uplink transmission over the shared radio frequency spectrum band in accordance with the autonomous uplink configuration and the A-DCI.

26. The method of claim 25, wherein the A-DCI comprises a bitmap of feedback information associated with one or more feedback processes associated with one or more autonomous uplink transmission.

27. The method of claim 26, wherein the feedback information comprises one or more acknowledgment/negative-acknowledgment (ACK/NACK) indications for one or more hybrid automatic repeat request (HARQ) processes.

28. The method of claim 26, wherein bits from two or more feedback processes are bundled.

29. The method of claim 25, wherein the A-DCI comprises uplink power control information for one or more autonomous uplink transmission.

30. The method of claim 25, further comprising:

receiving a channel quality indicator (CQI) or a modulation and coding scheme (MCS) indicator in the A-DCI over a shared channel transmission; and

transmitting an acknowledgment that the CQI or MCS are received.