Method for adjusting contention window size on basis of HARQ-ACK information in wireless access system supporting unlicensed band, and device for supporting same

• US 10,681,744 B2
• Filed: 01/08/2019
• Issued: 06/09/2020
• Est. Priority Date: 05/12/2015
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Seonwook, Ahn, Joonkui, Yang, Suckchel, Kim, Kijun, Kim, Byounghoon, Seo, Hanbyul, Park, Hanjun, Hwang, Daesung
• Primary Examiner(s): Mew, Kevin D
• Application Number:
  US16/242,804
• Publication Number:
  US 20190150194A1
• Time in Patent Office: 518 Days
• CPC Class Codes: H04L 1/00 Arrangements for detecting or preventing errors in the information received correcting synchronisation H04L7/00
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/187 Details of sliding window management
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 5/00 Arrangements affording multiple use of the transmission path
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04W 28/26 Resource reservation
• CPC Class Codes: H04W 74/085 collision avoidance
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]

Abstract

The present invention relates to a wireless access system that supports an unlicensed band, and provides various methods for adjusting a contention window size, methods for determining the time when the adjusted contention window size is applied, methods for distinguishing between a collision and a channel error, and devices for supporting the same. As an embodiment of the present invention, a method for adjusting a contention window size in a wireless access system supporting an unlicensed band may comprise the steps of: performing a channel access procedure; when it is determined through the performed channel access procedure that a serving cell (Scell) in the unlicensed band is in an idle state, transmitting a transmission burst including a downlink signal through the unlicensed band; receiving hybrid automatic repeat and request acknowledgment (HARQ-ACK) information corresponding to the transmission burst; and adjusting the CWS using the number of DTX states in the HARQ-ACK information when the transmission burst is scheduled in a self-carrier scheduling scheme.

Claims

1. A method for adjusting a contention window size (CWS) in a wireless access system supporting an unlicensed band, the method comprising:

performing a channel access procedure;

transmitting a transmission burst comprising a downlink signal in the unlicensed band based on the channel access procedure;

receiving hybrid automatic repeat and request acknowledgment (HARQ-ACK) information for the transmission burst; and

adjusting the CWS based on a number of negative acknowledgement (NACK) states in the HARQ-ACK information,

wherein based on the transmission burst being scheduled by a self-carrier scheduling, a discontinuous transmission (DTX) state in the HARQ-ACK information is counted as a NACK state for adjusting the CWS, and

wherein based on the transmission burst being scheduled by a cross-carrier scheduling, the DTX state is ignored for adjusting the CWS.

2. The method of claim 1, wherein a NACK/DTX state and an ANY state in the HARQ-ACK information are also counted as the NACK state for adjusting the CWS.

3. The method of claim 1, wherein based on the transmission burst being scheduled by the self-carrier scheduling, the number of the NACK states in the HARQ-ACK information is a number of NACK states in HARQ-ACK information related to a first subframe of the transmission burst.

4. A transmission node configured to adjust a contention window size (CWS) in a wireless access system supporting an unlicensed band, the transmission node comprising:

a memory; and

at least one processor coupled with the memory,

wherein the at least one processor is configured to;

perform a channel access procedure;

transmit a transmission burst comprising a downlink signal in the unlicensed band based on the channel access procedure;

obtain hybrid automatic repeat and request acknowledgment (HARQ-ACK) information related to the transmission burst; and

adjust the CWS based on a number of negative acknowledgement (NACK) states in the HARQ-ACK information,

wherein based on the transmission burst being scheduled by a self-carrier scheduling, a discontinuous transmission (DTX) state in the HARQ-ACK information is counted as a NACK state for adjusting the CWS, and

wherein based on the transmission burst being scheduled by a cross-carrier scheduling, the DTX state is ignored for adjusting the CWS.

5. The transmission node of claim 4, wherein a NACK/DTX state or an ANY state in the HARQ-ACK information is also counted as the NACK state for adjusting the CWS.

6. The transmission node of claim 4, wherein based on the transmission burst being scheduled by the self-carrier scheduling, the number of the NACK states in the HARQ-ACK information is a number of NACK states in HARQ-ACK information related to a first subframe of the transmission burst.