LTE Scheduling Request Signal Transmission Timing Determination
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Solution Overview
Problem
In LTE systems, user equipment (UE) cannot reliably determine the radio frame and subframe for sending scheduling request (SR) signals, leading to inefficient utilization of radio frames and potential unreliability in signal reception by the base station.
Innovation Solution
The UE determines the radio frame and subframe for sending SR signals by shifting the SR subframe offset from the starting subframe of consecutive radio frames, with specific equations used to calculate the system frame number and time slot index based on SR periodicity and subframe offset, ensuring accurate frame and subframe determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If the UE uses the SR configuration index to determine SR sending periodicity and subframe offset, then the UE can obtain SR transmission parameters, but the UE cannot reliably determine the specific radio frame and subframe for SR signal transmission
Solution Approach 1:
The patent performs preliminary calculations to determine the starting subframe of consecutive radio frames before determining the actual SR transmission subframe. By pre-calculating the frame sequence and applying the subframe offset to the starting subframe, the system establishes a reliable timing reference that ensures accurate SR transmission timing.
Solution Approach 2:
The patent segments the SR transmission timing determination into distinct steps: first determining the SR sending periodicity, then identifying consecutive radio frames, finding the starting subframe, and finally calculating the actual transmission subframe by applying the offset. This segmentation makes the timing determination process systematic and reliable.
2Productivity
If the UE determines SR transmission timing without considering radio frame time length relative to SR periodicity, then the determination process is simplified, but radio frames cannot be utilized sufficiently and effectively
Solution Approach 1:
The patent introduces dynamic adjustment by comparing the radio frame time length with the SR periodicity. Based on this comparison, the system dynamically selects different determination approaches: when frame length is sufficient, each frame can be used; when frame length is insufficient, multiple consecutive frames are considered. This dynamic approach optimizes radio frame utilization while adapting to different SR periodicity requirements.
Solution Approach 2:
The patent changes the determination parameters based on the relationship between radio frame time length and SR periodicity. When the frame length is less than the SR periodicity, the system adjusts by considering multiple consecutive frames and calculating an appropriate starting subframe, thereby optimizing the utilization of available radio frame resources.
3Ease of operation
If the UE sends SR signal without accurate frame and subframe determination, then the transmission process is simpler, but the base station cannot receive the SR signal reliably
Solution Approach 1:
The patent enables the UE to self-determine the correct SR transmission timing by using its own locally configured SR periodicity and subframe offset parameters combined with the determined starting subframe. This self-service approach allows the UE to autonomously calculate the correct transmission subframe without requiring additional network coordination, maintaining operational simplicity while ensuring reliable timing.
Data Source
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AI summary
A method and device for sending a scheduling request (SR) signal are used for a user equipment (UE) in a long term evolution system to send an uplink signal to a base station. The method includes: if a time length of a radio frame is less than an SR periodicity, a sending frame and a subframe for the SR signal are determined after shifting an SR subframe offset from a starting subframe of a first radio frame of multiple consecutive radio frames which have a total time length equal to the SR periodicity; if a time length of a radio frame is equal to or greater than the SR periodicity, each radio frame is determined as the sending frame for the SR signal, and if a time length of a radio frame is equal to the SR periodicity, a subframe of the sending frame is determined after shifting the SR subframe offset from the starting subframe of the sending frame; if a time length of a radio frame is greater than the SR periodicity, a subframe of the sending frame is determined after shifting the SR subframe offset from the starting subframe of a radio half-frame; and the UE sends the SR signal to the base station in the determined subframe of the sending frame.