Channel detection method, terminal and base station

Patent metadata

Field	Value
Publication number	US-10404389-B2
Application number	US-201715622925-A
Country	US
Kind code	B2
Filing date	Jun 14, 2017
Priority date	Dec 19, 2014
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

In one aspect of the disclosure, a channel detection method applied when an LTE system works in an unlicensed frequency band comprises determining a current sub-frame and a channel detection time when a data traffic arrives, wherein the channel detection time is set in at least one of the current sub-frame and a next adjacent sub-frame to perform channel state detection, and judging whether the terminal or base station that performs the channel state detection and other terminals or base stations belong to a same telecommunication operator in order to perform the channel state detection in a corresponding way; and performing data traffic transmission when it is detected that the channel is in an idle state. Other aspects of the disclosure relates to a terminal and a base station using the channel detection method.

First claim

The invention claimed is:

1. A channel detection method applied when an LTE system works in an unlicensed frequency band, characterized in comprising:
determining a current sub-frame and a channel detection time when a data traffic arrives, wherein the channel detection time is set in at least one of the current sub-frame and a next adjacent sub-frame to perform channel state detection, and judging whether the terminal or base station that performs the channel state detection and other terminals or base stations concurrently performing data transmission with the terminal or base station that performs the channel state detection belong to a same telecommunication operator;
if it is judged that the terminal or base station that performs the channel state detection and other terminals or base stations belong to a same telecommunication operator,
subtracting a second power of the other terminals or base stations from a first power detected by said terminal or base station that performs the channel state detection so as to attain a third power, and comparing the third power with a first channel busy-idle threshold value in order to perform the channel state detection; or
setting a second channel busy-idle threshold value according to the distribution of all the base stations belonging to the same telecommunication operator, and comparing the power detected by the terminal or base station with the second channel busy-idle threshold value in order to perform the channel state detection, wherein the second channel busy-idle threshold value includes the power of the other terminals or base stations;

and
performing data traffic transmission when it is detected that the channel is in an idle state.

2. The channel detection method according to claim 1 , characterized in that, when the data traffic arrives, determining a current symbol of the current sub-frame, and setting the channel detection time within at least one of the current symbol and a next adjacent symbol to perform the channel state detection.

3. The channel detection method according to claim 2 , characterized in that, setting a starting point of the channel detection time to be a starting point or middle point of at least one of the current sub-frame and the next adjacent sub-frame, or to be a starting point or middle point of at least one of the current symbol and the next adjacent symbol, wherein, the starting point or middle point is arranged after an arriving time point of the data traffic.

4. The channel detection method according to claim 3 , characterized in that, the channel state detection is repeated according to a fixed detection period.

5. The channel detection method according to claim 3 , characterized in that, the channel state detection is repeated according to a variable detection period.

6. The channel detection method according to claim 5 , characterized in that, when the data traffic arrives, determining the channel detection time and performing one time of the channel state detection, and if the channel is detected to be in an idle state, performing the data traffic transmission; if the channel is detected to be in a busy state, continuing performing the channel state detection.

7. The channel detection method according to claim 5 , characterized in that,
before the data traffic arrives, performing the channel state detection repeatedly according to a preset fixed detection period;
when the data traffic arrives, after the channel detection time is determined, performing a first time of channel state detection, and if the channel is detected to be in an idle state, performing the data traffic transmission; if the channel is detected to be in a busy state, performing again the channel state detection when reaching a fixed channel detection time point according to the preset fixed detection period, and repeatedly performing the channel state detection according to the preset fixed detection period until the channel is detected to be in an idle state, and then performing the data traffic transmission.

8. The channel detection method according to claim 2 , characterized in that, when the channel detection time is over at a point located at a middle point of a current symbol, starting to perform the data traffic transmission at a starting point of a symbol or sub-frame next to the current symbol, and transmitting a resource reservation signal or a channel idle state indication signal between the middle point of the current symbol and the starting point of the symbol or sub-frame next to the current symbol.

9. The channel detection method according to claim 1 , characterized in that,
when the data traffic is a downlink data traffic, downlink channel state detection is performed by a base station; and
when the data traffic is an uplink data traffic, uplink channel state detection is performed by a terminal or a base station.

10. The channel detection method according to claim 9 , characterized in that, when the base station performs the uplink channel state detection, judging whether an idle state of the uplink channel is known to at least one of the terminal and the base station,
if it is judged that the idle state of the uplink channel is known to at least one of the terminal and the base station, performing the uplink data traffic transmission;
if it is judged that the idle state of the uplink channel is not known to both the terminal and the base station, the terminal notifies the base station of the arrival of an uplink data traffic by sending a detection reference signal in short cycles, or sending an uplink scheduling request signal, or sending a cache status report to the base station, so as to cause the base station to perform the uplink channel state detection, wherein the uplink scheduling request signal or the cache status report is sent in an unlicensed frequency band or in a licensed frequency band.

11. The channel detection method according to claim 1 , characterized in that, when the channel detection time is over and the channel is detected to be in an idle state, immediately performing the data traffic transmission, wherein the start time of the data traffic transmission includes a middle point of a symbol or a middle point of a sub-frame.

12. The channel detection method according to claim 1 , characterized in that, if it is judged that the terminal or base station that performs the channel state detection and other terminals or base stations belong to different telecommunication operators,
the different telecommunication operators send channel occupation signals on subcarriers different from each other, and a subcarrier used to send one channel occupation signal is only used to send the one channel occupation signal; and when a terminal or a base station performs the channel state detection, the detected power includes the power of subcarriers used to send the channel occupation signals by telecommunication operators other than the same telecommunication operator that the terminal or the base station that performs the channel state detection belongs to, wherein, the subcarrier distribution of said same telecommunication operator is concentrated type or distributed type.

13. The channel detection method according to claim 1 , characterized in that, if downlink data traffic arrives at a base station when the terminal is performing uplink data traffic transmission,
starting to perform the channel state detection at a time point that is less than or equal to 4 ms after the arriving time of the downlink data traffic; or
if it is judged that the terminal or base station that performs the channel state detection and other terminals or base stations belong to different telecom

Assignees

• Yulong Computer Telecommunication Scientific Shenzhen Co Ltd
• Nanchang Coolpad Intelligent Tech Company Limited

Inventors

• Li Mingju
• Zhu Yajun
• Zhang Chenlu
• Lei Yixue
• Zhang Yunfei

Classifications

• H04W72/52

  based on load · CPC title

• H04W72/21

  in the uplink direction of a wireless link, i.e. towards the network · CPC title

• H04B17/19

  Self-testing arrangements · CPC title

• H04B17/382 Primary

  for resource allocation, admission control or handover · CPC title

• H04B17/391

  Modelling the propagation channel · CPC title