Method and apparatus for reducing self-jamming of transmissions on adjacent carriers

Patent metadata

Field	Value
Publication number	US-9860776-B2
Application number	US-201514743825-A
Country	US
Kind code	B2
Filing date	Jun 18, 2015
Priority date	Jun 20, 2014
Publication date	Jan 2, 2018
Grant date	Jan 2, 2018

Abstract

The present disclosure provides methods and apparatuses for multi-carrier transmissions over adjacent channels that reduce self-jamming due to asymmetric interference. In an aspect, a large bandwidth load-base equipment (LBE) carrier may be provided such that CCA is performed jointly over the entire bandwidth. In another aspect, additional CCA timeslots may be used to synchronize the two carriers. In a further aspect, an extended CCA may be performed on a primary unlicensed carrier while a simple CCA may be performed on a secondary unlicensed carrier. In yet another aspect, LBE may be deployed on some carriers while frame-base equipment (FBE) may be deployed on other carriers.

First claim

What is claimed is:

1. A method of wireless communication, comprising:
receiving data for transmission over at least two unlicensed carriers, the at least two unlicensed carriers including a first unlicensed carrier and a second unlicensed carrier;
performing an extended clear channel assessment (ECCA) countdown during a set of time slots on the first unlicensed carrier;
determining a potential last timeslot from one or more potential last timeslots of the ECCA countdown during the set of time slots on the first unlicensed carrier; and
performing, in response to the determination of the potential last timeslot, a clear channel assessment (CCA) check on the second unlicensed carrier during the potential last timeslot.

2. The method of claim 1 , further comprising:
determining if the ECCA countdown of the first unlicensed carrier is clear during the potential last timeslot; and
determining if the CCA check of the second unlicensed carrier is clear during the potential last timeslot.

3. The method of claim 2 , further comprising:
transmitting the data on one or more of the first unlicensed carrier or the second unlicensed carrier when one or more of the ECCA countdown of the first unlicensed carrier is clear during the potential last timeslot or the CCA check of the second unlicensed carrier is clear during the potential last timeslot.

4. The method of claim 2 , further comprising:
entering a freeze state on the second unlicensed carrier until the ECCA countdown of the first unlicensed carrier clears when the ECCA countdown of the first unlicensed carrier is not clear during the potential last timeslot; and
transmitting the data on one or more of the first unlicensed carrier or the second unlicensed carrier when the ECCA countdown of the first unlicensed carrier clears.

5. The method of claim 2 , further comprising:
remaining idle on the first unlicensed carrier for at least one additional timeslot after the potential last timeslot until the CCA check of the second unlicensed carrier clears when the CCA check of the second unlicensed carrier is not clear during the potential last timeslot; and
transmitting the data on one or more of the first unlicensed carrier or the second unlicensed carrier when the CCA check of the second unlicensed carrier clears.

6. The method of claim 1 , further comprising receiving, from a base station, a schedule for transmitting the data over one or more of the at least two unlicensed carriers.

7. The method of claim 6 , wherein the schedule indicates at least one of:
a maximum number of timeslots for remaining idle on the first unlicensed carrier;
a validity of a resource grant on at least one of the first unlicensed carrier or the second unlicensed carrier; or
a priority among unlicensed carriers for transmitting the data to the base station.

8. The method of claim 6 , wherein the schedule comprises information related to transmitting a physical uplink control channel (PUCCH).

9. A method of wireless communication, comprising:
receiving data for transmission over at least two unlicensed carriers, the at least two unlicensed carriers including a first unlicensed carrier and a second unlicensed carrier;
performing an extended clear channel assessment (ECCA) countdown during a set of time slots on each of the at least two unlicensed carriers;
determining a potential last timeslot from one or more potential last timeslots of the ECCA countdown during the set of time slots on the second unlicensed carrier; and
performing, in response to the determination of the potential last timeslot, a clear channel assessment (CCA) check on the first unlicensed carrier during the potential last timeslot.

10. The method of claim 9 , further comprising remaining idle on the first unlicensed carrier during at least one timeslot after the ECCA countdown of the first unlicensed carrier until the potential last timeslot of the ECCA countdown on the second unlicensed carrier is reached.

11. The method of claim 10 , further comprising:
determining if the CCA check on the first unlicensed carrier is clear during the potential last timeslot; and
determining if the ECCA countdown on the second unlicensed carrier is clear during the potential last timeslot.

12. The method of claim 11 , further comprising:
transmitting the data on one or more of the first unlicensed carrier or the second unlicensed carrier when one or more of the CCA check of the first unlicensed carrier is clear during the potential last timeslot or the ECCA countdown of the second unlicensed carrier is clear during the potential last timeslot.

13. The method of claim 11 , further comprising:
entering a freeze state on the second unlicensed carrier until the CCA check clears when the CCA check of the first unlicensed carrier is not clear during the potential last timeslot; and
transmitting the data on one or more of the first unlicensed carrier or the second unlicensed carrier when the CCA check clears the first unlicensed carrier.

14. The method of claim 11 , further comprising:
remaining idle on the first unlicensed carrier for at least one additional timeslot after the potential last timeslot until the ECCA countdown of the second unlicensed carrier clears when the ECCA countdown of the second unlicensed carrier is not clear during the potential last timeslot; and
transmitting the data on one or more of the first unlicensed carrier or the second unlicensed carrier when the ECCA countdown on the second unlicensed carrier clears.

15. The method of claim 9 , wherein the performing the CCA check comprises:
determining a potential number of timeslots between an end of the ECCA countdown of the first unlicensed carrier and the potential last timeslot in which the ECCA countdown of the second unlicensed carrier ends; and
performing the CCA check on the first unlicensed carrier when the potential number of timeslots is greater than a threshold.

16. The method of claim 9 , wherein the performing the CCA check comprises:
determining a first potential countdown value for performing the ECCA countdown of the first unlicensed carrier;
determining a second potential countdown value between an end of the ECCA countdown of the first unlicensed carrier and an end of the ECCA countdown of the second unlicensed carrier; and
performing the CCA check on the first unlicensed carrier when a duty cycle is greater than a threshold, wherein the duty cycle is equal to the second potential countdown value divided by a sum of the first potential countdown value and the second potential countdown value.

17. The method of claim 9 , further comprising receiving, from a base station, a schedule for transmitting over one or more of the at least two unlicensed carriers.

18. The method of claim 17 , wherein the schedule indicates at least one of:
a maximum number of timeslots for remaining idle on the first unlicensed carrier;
a validity of a resource grant on at least one of the first unlicensed carrier or the second unlicensed carrier; or
a priority among unlicensed carriers for transmission to the base station.

19. The method of claim 17 , wherein the schedule comprises information related to transmitting a physical uplink control channel (PUCCH).

20. A method of wireless communication, comprising:
receiving data for transmission over at least two unlicensed carriers, the at least two unlicensed carriers including a first unlicensed carrier and a second unlicensed carrier;
performing an extended clear channel assessment (ECCA) cou

Assignees

• Qualcomm Inc

Inventors

• Yerramalli Srinivas
• Luo Tao
• Somasundaram Kiran Kumar
• Malladi Durga Prasad
• Bhushan Naga
• Wei Yongbin
• Damnjanovic Aleksandar
• Chen Wanshi
• Zhang Xiaoxia
• Xu Hao
• Sukhavasi Ravi Teja

Classifications

• H04W24/08 Primary

  Testing, {supervising or monitoring} using real traffic · CPC title

• H04W74/0808 Primary

  using carrier sensing, e.g. carrier sense multiple access [CSMA] · CPC title