METHOD AND APPARATUS FOR TRANSMITTING DATA IN WIRELESS COMMUNICATION SYSTEM

• US 20180255577A1
• Filed: 09/02/2016
• Published: 09/06/2018
• Est. Priority Date: 09/04/2015
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: LEE, Jeongho, MAENG, Seungjoo, KHO, Youngsung, KIM, Hanseok, HAN, Kyuho
• Granted Patent: US 11,096,215 B2
• Time in Patent Office: Days
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 28/26 Resource reservation
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 74/00 Wireless channel access
• CPC Class Codes: H04W 74/002 Transmission of channel access control information
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]

Abstract

The present invention relates to a method and apparatus for transmitting data in a mobile communication system and, more particularly, to a method and apparatus for transmitting data by a base station in an unlicensed frequency. To achieve the above described problem, a method for transmitting data by a base station in a wireless communication system according to an embodiment of the present invention may comprise the steps of: transmitting a first signal for determining whether a data transmission is possible in an unlicensed frequency band; transmitting a second signal for reserving a data transmission in the unlicensed frequency band when the data transmission in the unlicensed frequency band is possible; and transmitting first data to a terminal through the unlicensed frequency band after transmitting the second signal. According to an embodiment of the present invention, a base station determines whether other communication devices do not use the unlicensed frequency band, and transmits a channel reservation signal having a period shorter than a resource allocation period during a predetermined period of time, thereby pursuing coexistence with other communication devices and improving the performance of a communication system at the same time.

Claims

1. A data transmission method of a base station in a wireless communication system, the method comprising:

determining whether data transmission is available in an unlicensed frequency band;

transmitting, if the data transmission is available in the unlicensed frequency band, a first reservation signal for reserving the unlicensed frequency band for transmitting data in a unit of a length shorter than a transmission time interval (TTI); and

transmitting first data to a terminal in the unlicensed frequency band after transmitting the first reservation signal.

2. The method of claim 1, wherein the first reservation signal is transmitted periodically before an end of a first subframe transmitting the first reservation signal, and the first data is transmitted in a second subframe arriving after the first subframe.

3. The method of claim 1, further comprising:

transmitting a second reservation signal for reserving the unlicensed frequency band for uplink transmission of the terminal after transmitting the first data; and

receiving second data transmitted from the terminal after transmitting the second reservation signal.

5. The method of claim 1,

wherein, if the transmission of the first reservation signal is identified by another base station, third data is transmitted to the terminal, by the another base station, in a subframe arriving after the subframe transmitting the first reservation signal.

6. The method of claim 5, wherein,

in the subframe transmitting the first reservation signal, whether another device uses the unlicensed frequency band is determined by the another base station, if the use of the unlicensed frequency band by the another device is not detected based on a result of the determination, the third data is transmitted.

7. The method of claim 5, wherein the transmission of the reservation signal is identified based on at least one of a basic service set identifier (BSSID) included in the first reservation signal and a service set identifier (SSID) and information contained in a message being exchanged through an X2 interface between base stations.

16. The method of claim 1, wherein the unit shorter than the TTI is 4 μ

s.

17. The method of claim 1, wherein the first reservation signal is transmitted using another communication module for transmitting a signal by the unit shorter than the TTI.

18. The method of claim 1, wherein if data transmission is scheduled in a unit of a symbol, the first reservation signal is transmitted periodically before a symbol scheduled for transmitting the first data and the first data is transmitted at a symbol arriving after the symbol transmitting the first reservation signal.

4. (canceled)

8. A base station for transmitting data in a wireless communication system, the base station comprising:

a transceiver configured to transmit and receive data; and

a controller configured to;

determine whether data transmission is available in an unlicensed frequency band,

control the transceiver to transmit, if the data transmission is available in the unlicensed frequency, a first reservation signal for reserving the unlicensed frequency band for transmitting data in a unit of a length shorter than a transmission time interval (TTI), and

first data to a terminal in the unlicensed frequency band after transmitting the first reservation signal.

9. The base station of claim 8, wherein the first reservation signal is transmitted periodically before an end of a first subframe transmitting the first reservation signal, and the first data is transmitted in a second subframe arriving after the first subframe.

10. The base station of claim 8, wherein the controller is further configured to:

control the transceiver to transmit a second reservation signal for reserving the unlicensed frequency band for uplink transmission of the terminal after transmitting the first data, and

receive second data transmitted from the terminal after transmitting the second reservation signal.

12. The base station of claim 8, wherein,

if the transmission of the first reservation signal is identified by another base station, third data is transmitted to the terminal, by the another base station, in a third subframe arriving after the subframe transmitting the first reservation signal.

13. The base station of claim 12, wherein, in the subframe transmitting the first reservation signal, whether another device uses the unlicensed frequency band is determined by the another base station, if the use of the unlicensed frequency band by the another device is not detected, based on a result of the determination, the third data is transmitted.

14. The base station of claim 12, wherein the transmission of the reservation signal is identified based on at least one of a basic service set identifier (BSSID) included in the first reservation signal and a service set identifier (SSID) and information contained in a message being exchanged through an X2 interface between base stations.

15. The base station of claim 8, wherein the controller is further configured to control the transceiver to transmit, if data communication is scheduled in a unit of a symbol, the second signal periodically before a symbol scheduled for transmitting the first data, the first data being transmitted at a symbol arriving after the symbol transmitting the second signal.

19. The base station of claim 8, wherein the unit shorter than the TTI is 4 μ

s.

20. The base station of claim 8, wherein the first reservation signal is transmitted using another communication module for transmitting signal by the unit shorter than the TTI.

11. (canceled)