METHOD FOR SUPPORTING HARQ IN COMMUNICATION SYSTEM USING UNLICENSED FREQUENCY BAND AND DEVICE HAVING APPLIED SAME

• US 20180131473A1
• Filed: 03/31/2016
• Published: 05/10/2018
• Est. Priority Date: 04/09/2015
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Moon, Jung-Min, Park, Seung-Hoon, Jung, Jung-Soo, Ryoo, Sun-Heui, Jung, Byoung-Hoon
• Granted Patent: US 10,333,654 B2
• Time in Patent Office: Days
• 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 1/1819 with retransmission of additional or different redundancy
• CPC Class Codes: H04L 1/1861 Physical mapping arrangements for ACK signaling see also H04L5/0053
• CPC Class Codes: H04L 1/1896 ARQ related signaling
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/0051 of dedicated pilots, i.e. pilots destined for a single user or terminal
• 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 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 74/004 in the uplink, i.e. towards network

Abstract

The present invention relates to 5G or pre-5G communication system for supporting a higher data transmission rate after 4G communication system such as LTE. The present invention provides a method and a device for executing a hybrid automatic repeat request (HARQ) through a channel in an unlicensed frequency band. More particularly, a method for executing a HARQ through a channel in an unlicensed frequency band in a terminal of a communication system comprises the procedures of: requesting uplink scheduling; if a first uplink (UL) grant with respect to the scheduling request is received, sensing whether or not a channel is clear; transmitting first uplink data on the basis of whether or not the channel is clear; if negative acknowledge (NACK) with respect to the first uplink grant and a second uplink grant are received, sensing whether or not the channel is clear; and transmitting second uplink data and an indicator, which indicates whether or not the second uplink data transmission is a retransmission, on the basis of whether or not the channel is clear, wherein the indicator, which indicates for retransmission, is determined on the basis of a reference signal (RS) detection failure indicator, of a base station, which is transmitted from the base station together with the second uplink grant.

Claims

1. A method for transmitting and receiving data by a terminal in a communication system, the method comprising:

receiving from a base station, a scheduling response associated with a scheduling request of the terminal;

identifying, based on the received scheduling response, a state of channel between the terminal and the base station; and

transmitting, based on the identified state of the channel, at least one of first uplink (UL) data, second UL data, or an indicator indicating whether the second UL data is re-transmitted data,

wherein the indicator indicating whether the second UL data is re-transmitted data, is determined based on a detection of a reference signal (RS) transmitted from the base station.

2. The method of claim 1, wherein the indicator indicating whether the second UL data is re-transmitted data is an indicator indicating that the second UL data is re-transmitted data, if the terminal transmits the first UL data because the channel is not occupied by other terminal, and the detection of RS is failed.

3. The method of claim 2, wherein the indicator indicating whether the second UL data is re-transmitted data further comprises a hybrid automatic repeat request (HARQ) redundancy version (RV) of the second UL data.

4. The method of claim 1, wherein the indicator indicating whether the second UL data is re-transmitted data is an indicator indicating that the second UL data is new data, if the terminal fails to transmit the first UL data because the channel is occupied by other terminal.

5. The method of claim 1, wherein the indicator indicating whether the second UL data is re-transmitted data is transmitted using a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH).

6. The method of claim 1, wherein the RS is a demodulation reference signal (DM-RS) or cell specific reference signal (CRS).

16. The method of claim 1, further comprising:

transmitting to the base station, the scheduling request;

identifying whether the channel is occupied by other terminal, upon receiving a first UL grant with respect to the scheduling request;

transmitting the first UL data according to whether the channel state is clear;

identifying whether the channel is occupied by other terminal, upon receiving a negative acknowledge (NACK) with respect to the first UL grant and a second UL grant; and

transmitting the second UL data and the indicator indicating whether the second UL data is re-transmitted data, according to whether the channel is occupied by other terminal.

7. A method for transmitting and receiving data by a base station in a communication system, the method comprising:

transmitting to a terminal, a first scheduling response with respect to a scheduling request of the terminal;

receiving first uplink (UL) data in response to the first scheduling response;

detecting a reference signal (RS) of first uplink (UL) data;

transmitting to the terminal, based on the identification of the RS, a second scheduling response and a first indicator indicating whether the detection of the RS is fails; and

receiving second UL data and a second indicator indicating whether the second UL data is re-transmitted data, in response to the second scheduling response.

8. The method of claim 17, wherein the processing of the second UL data comprises:

soft-combining the first UL data with the second UL data, if the second indicator indicates that the second UL data is re-transmitted data.

9. The method of claim 17, wherein the processing of the second UL data comprises:

discarding the first UL data, if the second indicator indicates that the second UL data is new data.

10. The method of claim 7, wherein the first indicator indicates that the detection of the RS is fails even if the first scheduling response is transmitted.

11. The method of claim 7, wherein the RS is a demodulation reference signal (DM-RS) or cell specific reference signal (CRS).

17. The method of claim 7, further comprising:

processing the second UL data according to the second indicator indicating whether the second UL data is re-transmitted data.

12. A terminal in a communication system for transmitting and receiving data, the terminal comprising:

a transceiver configured to communicate with a base station; and

a processor coupled with the transceiver and configured to;

receive a scheduling response associated with a scheduling request of the terminal,

identify, based on the received scheduling response, a state of a channel between the terminal and the base station, and

transmit, based on the identified state of the channel, at least one of first uplink (UL) data, second UL data, or an indicator indicating whether the second UL data is re-transmitted data,

wherein the indicator indicating whether the second UL data is re-transmitted data is determined based on a detection of a reference signal (RS) transmitted from the base station.

19. The terminal of claim 12,

wherein the processor further configured to:

transmit a scheduling request,

identify whether the channel is occupied by other terminal, upon receiving a first UL grant with respect to the scheduling request,

transmit first UL data according to whether the channel is clear, and

identify whether the channel is occupied by other terminal, upon receiving a negative acknowledge (NACK) with respect to the first UL grant and a second UL grant, and

transmit second UL data and an indicator indicating whether the second UL data is re-transmitted data, according to whether the channel is occupied by other terminal.

13. (canceled)

14. A base station in a communication system for transmitting and receiving data, the base station comprising:

a transceiver configured to communicate with a terminal; and

a processor coupled with the transceiver and configured to;

transmit a first scheduling response with respect to a scheduling request of the terminal,

receive first uplink (UL) data in response to the first scheduling response,

detect a reference signal (RS) of first uplink (UL) data,

transmit to the terminal, based on the identification of the RS, a second scheduling response and a first indicator indicating whether the identification of the RS is fails,

transmit a second UL grant depending on whether the detection of RS is fails, and

receive second UL data and a second indicator indicating whether the second UL data is re-transmitted data, in response to the second scheduling response.

20. The base station of claim 14, wherein the processor further configured to:

process the second UL data according to the second indicator indicating whether the second UL data is re-transmitted data.

15. (canceled)

18. The method of 7, wherein the receiving the first UL data and the second UL data is based on a channel state between the terminal and the base station, the state of the channel identified by the terminal.

21. The base station of 14, wherein the processor further configured to:

receive the first UL data or the second UL data based on a state of a channel between the terminal and the base station, the state of the channel identified by the terminal.