Incomplete Subframe Position Indication for LTE-U Transmission
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Solution Overview
Problem
Existing technologies lack a solution for efficiently transmitting data using incomplete subframes in unauthorized frequency bands, leading to reduced transmission efficiency and resource wastage in LTE-U systems.
Innovation Solution
A method is provided where a network device determines the starting position of to-be-transmitted data in a radio frame and transmits position indication information to a terminal, allowing the terminal to accurately determine the starting position and receive data in incomplete subframes within the unauthorized frequency band.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If incomplete subframes are not used for transmission to ensure fair competition, then competition fairness between LTE-U and Wi-Fi is maintained, but transmission efficiency of LTE-U is greatly decreased
Solution Approach 1:
The patent applies dynamics by making the subframe structure adaptable - complete subframes are used when the unauthorized frequency band is available, while incomplete subframes are used when channel access is delayed. The system dynamically adjusts between these two modes based on LBT outcomes and channel conditions, resolving the contradiction between maintaining competition fairness and achieving high transmission efficiency.
Solution Approach 2:
The patent changes the time duration parameter of subframes from a fixed 1ms to variable lengths including incomplete subframes. By introducing position indication information to mark the starting position of incomplete subframes, the system enables flexible parameter adjustment that allows efficient utilization of available transmission opportunities while maintaining fair competition through LBT mechanisms.
2Productivity
If incomplete subframes are transmitted to enhance data transmission efficiency, then resource utilization is improved, but terminals cannot determine the starting position of data in the incomplete subframe
Solution Approach 1:
The patent introduces position indication information as an intermediary element that bridges the gap between the network device and terminal. This indicator acts as a mediator that conveys the starting position of data in incomplete subframes from the network device to the terminal, enabling the terminal to correctly identify and receive data without losing position information.
Solution Approach 2:
The patent applies preliminary action by pre-defining and signaling the starting position of incomplete subframes using position indication information before actual data transmission begins. This allows terminals to prepare their reception timing in advance, ensuring they can accurately capture data in incomplete subframes without losing synchronization.
3Reliability
If LBT competitive access is implemented in unauthorized frequency band, then fair co-existence with other wireless systems is achieved, but data preparation time and radio frequency preparation time cause transmission delays
Solution Approach 1:
The patent applies periodic action through the LBT mechanism that periodically checks channel availability before transmission. By implementing listen-before-talk at regular intervals and using position indication information to mark actual transmission start points, the system achieves fair periodic access to unauthorized frequency bands while minimizing time loss by immediately transmitting data when the channel becomes available.
Data Source
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AI summary
The present disclosure relates to the field of mobile communications technology. A Method and a device for transmitting data in an unauthorized frequency band are provided. The method includes: determining a starting position of to-be-transmitted data in a radio frame in the unauthorized frequency band; determining position indication information based on the starting position; and transmitting the position indication information, to enable a terminal to obtain the starting position of the to-be-transmitted data in the radio frame in the unauthorized frequency band based on the position indication information.