Uplink Timing Determination Using Absolute Time Reference
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Solution Overview
Problem
In wireless communication systems, particularly in next-generation networks like 5G, determining uplink transmission timing accurately is challenging due to factors like large one-way propagation delays in non-terrestrial networks, which can lead to increased latency and synchronization delays, affecting the efficiency and reliability of communication.
Innovation Solution
A method where User Equipment (UE) determines the uplink transmission timing based on absolute time, independent of downlink reception timing, using its internal clock and potentially GPS information for precise timing, allowing for flexible subframe and slot initiation without relying on relative timing advances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If UE determines uplink transmission timing based on downlink reception timing with timing advance, then synchronization is maintained in traditional networks, but latency increases and synchronization delays occur in non-terrestrial networks with large propagation delays
Solution Approach 1:
The patent inverts the traditional timing determination approach by having the UE determine uplink transmission timing based on absolute time (UTD) from its own clock rather than relative to downlink reception timing. This inversion eliminates the dependency on downlink timing and timing advance adjustments, directly reducing latency while maintaining synchronization through absolute time reference at the network side.
Solution Approach 2:
The UE autonomously determines its uplink transmission timing using its internal clock and absolute time information, without requiring continuous timing advance adjustments from the network. This self-service approach reduces the interaction overhead and timing adjustment delays, improving both latency and synchronization reliability in non-terrestrial networks.
2Adaptability or versatility
If UE uses relative timing advance for uplink transmission, then timing synchronization is achieved in traditional networks, but flexibility in subframe and slot initiation is reduced
Solution Approach 1:
The patent replaces the relative timing advance mechanism with absolute time determination. The UE initiates uplink transmissions at predetermined absolute times based on its clock, providing flexibility in subframe and slot initiation while maintaining timing synchronization through the absolute time reference framework established by the network.
Data Source
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AI summary
A method and apparatus are disclosed from the perspective of a User Equipment (UE). In one embodiment, the UE performs an Uplink (UL) transmission of an UL signal to a base station in an UL subframe wherein the UL subframe begins at a timing derived based on an absolute time (2005).