LTE Unlicensed Channel Detection Sub-Frame Configuration
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Solution Overview
Problem
LTE systems operating in unlicensed frequency bands cause significant interference to other devices like Wi-Fi due to the lack of an interference avoidance mechanism, leading to poor coexistence and potential service disruptions.
Innovation Solution
A control method for configuring a channel detection sub-frame is introduced, where downlink and uplink channel detection sub-frames are set within the frame structure to periodically check the idle state of the channels, allowing data transmission only when the channels are detected as idle, thereby preventing interference and ensuring peaceful coexistence with other systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If LTE system transmits data continuously in unlicensed band without monitoring, then LTE spectral efficiency and coverage are improved, but interference to Wi-Fi and other systems increases significantly
Solution Approach 1:
The patent applies preliminary action by implementing channel monitoring before data transmission. The LTE system performs LBT (Listen Before Talk) procedures and checks channel status in monitoring sub-frames before initiating downlink or uplink data transmission. This preliminary channel assessment prevents interference to Wi-Fi and other unlicensed band users by ensuring the channel is idle before LTE transmission begins.
Solution Approach 2:
The patent implements feedback mechanisms where the LTE system continuously monitors channel occupancy and receives feedback about channel status from both base station and terminal sides. The system adjusts transmission decisions based on this feedback, dynamically switching between transmission and monitoring states to coexist fairly with other unlicensed band users while maintaining LTE performance.
2Reliability
If LTE system implements channel monitoring to avoid interference, then coexistence with Wi-Fi is improved, but system complexity and transmission overhead increase
Solution Approach 1:
The patent applies segmentation by dividing the LTE frame structure into distinct monitoring sub-frames and data transmission sub-frames. Channel monitoring is performed in specific designated sub-frames (e.g., first and last sub-frames of a frame), while data transmission occurs in other sub-frames. This segmentation organizes the complexity into manageable, periodic monitoring intervals rather than continuous monitoring, reducing overall system complexity.
Solution Approach 2:
The patent implements periodic channel monitoring where the LTE system checks channel status at regular intervals (e.g., every frame or every few sub-frames) rather than continuously. This periodic LBT approach maintains reliable coexistence with Wi-Fi by ensuring periodic channel availability checks while reducing the complexity and overhead compared to continuous monitoring, allowing data transmission in between monitoring instances.
3Object-generated harmful factors
If channel monitoring sub-frame is added to frame structure, then interference avoidance is achieved, but available data transmission time is reduced
Solution Approach 1:
The patent applies partial action by implementing channel monitoring only in specific sub-frames (e.g., first and last sub-frames of a frame) rather than in every sub-frame. Data transmission can proceed in the intermediate sub-frames without monitoring overhead. This partial monitoring approach achieves sufficient interference avoidance for coexistence while minimizing the loss of data transmission time, as not all sub-frames are consumed by monitoring activities.
Data Source
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AI summary
A data transmission method, a data transmission system, a control method, a control system, and a device having a base station function. The control method includes: setting, in a frame structure in a time division duplex mode, a downlink channel detection sub-frame used for periodically detecting whether a downlink channel of an unlicensed frequency band is idle(502); and sending an uplink channel detection sub-frame configuration command to a terminal according to a configuration mode of the downlink channel detection sub-frame, so that the terminal sets, in the frame structure according to the uplink channel detection sub-frame configuration command, an uplink channel detection sub-frame used for periodically detecting whether an uplink channel of the unlicensed frequency band is idle(504). By means of the technical solution, an LTE system operating in an unlicensed frequency band can be prevented from causing great interference to other systems while ensuring normal operation of the LTE system in the unlicensed frequency band, so that peaceful coexistence of the LTE system and other systems in the unlicensed frequency band is achieved.