UPLINK TRANSMISSION TECHNIQUES IN SHARED SPECTRUM WIRELESS COMMUNICATIONS

• US 20190014481A1
• Filed: 06/29/2018
• Published: 01/10/2019
• Est. Priority Date: 07/05/2017
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Yerramalli, Srinivas, Radulescu, Andrei Dragos, Luo, Tao, Kadous, Tamer, Damnjanovic, Aleksandar
• Granted Patent: US 10,687,219 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• 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
• CPC Class Codes: H04W 76/27 Transitions between radio resource control [RRC] states

Abstract

Methods, systems, and devices for wireless communication are described. The described techniques provide for transmission of uplink data from a user equipment (UE) in the absence of scheduled uplink resources for the uplink data transmission that are allocated to the UE prior to the transmission of the uplink data. Various examples provide frame structures that may be used for unscheduled uplink transmissions of a UE. Unscheduled uplink transmissions may be transmitted in a shared or unlicensed radio frequency spectrum, and access to the shared or unlicensed radio frequency spectrum may be determined based on a priority of an operator associated with a UE for accessing the spectrum. Beamforming techniques may be used for uplink and downlink transmissions and beam widths for beamformed transmissions may be selected based on the information transmitted in a transmission, an operator priority for use of shared radio frequency spectrum, or any combination thereof.

Claims

1. A method for wireless communication, comprising:

identifying, at a user equipment (UE), wireless resources within a shared radio frequency spectrum band that are configured for unscheduled uplink transmissions within a self-contained transmission opportunity;

determining that at least a portion of the identified wireless resources is available for an unscheduled uplink transmission; and

transmitting the unscheduled uplink transmission during the self-contained transmission opportunity based at least in part on the determining.

2. The method of claim 1, wherein the identifying comprises:

identifying one or more self-contained transmission opportunities that are configured for unscheduled uplink transmissions, the one or more self-contained transmission opportunities comprising first resources for uplink data transmissions and second resources for downlink transmissions responsive to the uplink data transmissions.

3. The method of claim 2, wherein the one or more self-contained transmission opportunities are semi-statically configured for unscheduled uplink transmissions.

4. The method of claim 2, wherein the determining comprises:

performing a listen-before-talk (LBT) procedure at the UE to determine availability of at least the portion of the identified wireless resources for the unscheduled uplink transmission.

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

receiving a first downlink transmission in a first portion of the self-contained transmission opportunity, the first downlink transmission indicating that a second portion of the self-contained transmission opportunity is configured for unscheduled uplink transmissions.

6. The method of claim 5, further comprising:

receiving a second downlink transmission responsive to the unscheduled uplink transmission during a third portion of the self-contained transmission opportunity, wherein the second downlink transmission comprises an acknowledgment indicating successful or unsuccessful receipt of the unscheduled uplink transmission.

7. The method of claim 5, wherein the configuration of the self-contained transmission opportunity for the unscheduled uplink transmission is dynamically indicated in the first downlink transmission.

8. The method of claim 5, further comprising:

measuring a channel quality of the identified wireless resources based at least in part on a reference signal in the first downlink transmission; and

determining one or more uplink transmission parameters for the unscheduled uplink transmission based at least in part on the channel quality.

9. The method of claim 1, wherein the identifying comprises:

identifying the self-contained transmission opportunity as configured for unscheduled uplink transmissions;

transmitting a first indication that the UE has uplink data to transmit; and

receiving a second indication that the UE is to transmit the uplink data during the self-contained transmission opportunity.

10. The method of claim 9, further comprising:

receiving, subsequent to transmitting the unscheduled uplink transmission, an acknowledgment indicating successful or unsuccessful receipt of the unscheduled uplink transmission.

11. The method of claim 1, further comprising:

receiving an acknowledgment of successful or unsuccessful receipt of the unscheduled uplink transmission in a downlink channel or in downlink control information (DCI) associated with the unscheduled uplink transmission.

12. The method of claim 1, further comprising:

receiving, subsequent to transmitting the unscheduled uplink transmission, an indication to continue or discontinue transmitting unscheduled uplink transmissions.

13. A method for wireless communication, comprising:

configuring, at a base station, wireless resources within a shared radio frequency spectrum band for unscheduled uplink transmissions within a self-contained transmission opportunity;

indicating, to a user equipment (UE), that the wireless resources within the self-contained transmission opportunity are configured for unscheduled uplink transmissions; and

receiving an unscheduled uplink transmission from the UE during the self-contained transmission opportunity.

14. The method of claim 13, wherein:

the configuring comprises configuring one or more self-contained transmission opportunities for unscheduled uplink transmissions, the one or more self-contained transmission opportunities comprising first resources for uplink data transmissions and second resources for downlink transmissions responsive to the uplink data transmissions; and

the indicating comprises transmitting, to the UE, configuration information that indicates the one or more self-contained transmission opportunities configured for unscheduled uplink transmissions.

15. The method of claim 14, wherein the one or more self-contained transmission opportunities are semi-statically configured for unscheduled uplink transmissions using a radio resource control (RRC) signaling or control resource set (CORESET).

16. The method of claim 13, wherein the indicating comprises:

transmitting a first downlink transmission in a first portion of the self-contained transmission opportunity, the first downlink transmission indicating that a second portion of the self-contained transmission opportunity is configured for unscheduled uplink transmissions.

17. The method of claim 16, wherein configuration of the self-contained transmission opportunity for unscheduled uplink transmissions is dynamically indicated in the first downlink transmission.

18. The method of claim 13, wherein the receiving further comprises:

receiving an indication, during a first portion of the self-contained transmission opportunity, that the UE has uplink data to transmit;

selecting the UE for transmitting the uplink data during the self-contained transmission opportunity; and

authorizing the UE is to transmit the uplink data during the self-contained transmission opportunity.

19. The method of claim 13, further comprising:

determining whether the unscheduled uplink transmission is successfully received; and

transmitting an acknowledgment of successful or unsuccessful receipt of the unscheduled uplink transmission in a downlink channel or in downlink control information (DCI) associated with the unscheduled uplink transmission.

20. The method of claim 13, further comprising:

transmitting, subsequent to receiving the unscheduled uplink transmission, an indication to continue or discontinue transmitting unscheduled uplink transmissions.

21. A method for wireless communication, comprising:

identifying, at a user equipment (UE), a first configuration or a second configuration for transmitting an unscheduled uplink transmission in a shared radio frequency spectrum band based at least in part on an operator priority for accessing the shared radio frequency spectrum band;

performing, based at least in part on the identified first configuration or second configuration, a listen-before-talk (LBT) procedure at the UE to determine availability of at least a portion of the identified wireless resources for the unscheduled uplink transmission; and

transmitting the unscheduled uplink transmission using the shared radio frequency spectrum band based at least in part on the LBT procedure.

22. The method of claim 21, wherein the performing the LBT procedure further comprises:

sensing that another transmitter is transmitting using at least the portion of the identified wireless resources;

determining a contention window (CW) duration based at least in part on the identified first configuration or second configuration; and

determining, upon expiration of the CW, whether another transmitter is transmitting using at least the portion of the identified wireless resources.

23. The method of claim 22, wherein the operator priority indicates whether an operator associated with the UE has a priority over one or more other operators in a time duration, and the first configuration provides a first set of channel access parameters for use when the operator associated with the UE has a higher priority than other operators, and the second configuration provides a second set of channel access parameters for use when the operator associated with the UE has a lower priority than at least one other operator, the second set of channel access parameters allowing channel access when at least the portion of the identified wireless resources are unused by the at least one other operator.

24. The method of claim 22, wherein the CW duration is set to a first value when the first configuration is used for the unscheduled uplink transmission and is set to a second value when the second configuration is used for the unscheduled uplink transmission.

25. The method of claim 22, wherein the CW duration is set to a first value for scheduled uplink transmission and is set to a second value for unscheduled uplink transmissions.

26. A method for wireless communication, comprising:

configuring, at a base station, wireless resources of one or more transmission beams within an unlicensed radio frequency spectrum band for unscheduled uplink transmissions by a user equipment (UE);

transmitting, to the UE, configuration information that indicates the wireless resources of the one or more transmission beams configured for unscheduled uplink transmissions; and

monitoring the configured wireless resources of the one or more transmission beams for an unscheduled uplink transmission from the UE.

27. The method of claim 26, further comprising:

configuring a beam width of the wireless resources of the one or more transmission beams based at least in part on an operator priority of an operator associated with the base station.

28. The method of claim 27, wherein the beam width is configured to be a wider beam width when the operator priority of the operator associated with the base station is a lower priority than one or more other operators, and is configured to be a narrower beam width when the operator priority of the operator associated with the base station is a higher priority than any other operators.

29. The method of claim 26, wherein the configuring further comprises:

configuring one or more of a transmission power offset, additional transmission bandwidth or time resources, or a modulation and coding scheme (MCS)/rank offset relative to a scheduled uplink transmission to compensate for beamforming loss associated with the unscheduled uplink transmission.

30. The method of claim 26, wherein the transmitting comprises:

transmitting the configuration information to a plurality of UEs in a common physical downlink control channel transmission having a wider transmission beam width than a transmission beam width of a physical downlink shared channel transmission to a single UE.