Uplink Timing Synchronization in Discontinuous Reception
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Maintaining uplink synchronization in wireless communication systems is challenging, particularly for user equipment (UE) with discontinuous reception (DRX) cycles, as it can lead to inefficient throughput and battery life reduction due to inconsistent data transmission.
Innovation Solution
Implementing a hybrid approach where the UE transmits uplink timing reference signals (SRS) during DRX 'On' periods and, in certain conditions, irrespective of DRX periods, with an uplink timing alignment timer to manage resource allocation and synchronization, allowing for flexible SRS and CQI sub-frame alignment to conserve power and maintain alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE transmits uplink timing reference signals continuously to maintain synchronization, then uplink synchronization is improved, but battery life deteriorates and throughput efficiency worsens
Solution Approach 1:
The patent implements periodic transmission of uplink timing reference signals (SRS) during DRX 'On' durations rather than continuous transmission. The UE transmits SRS periodically at configured intervals only when the DRX active timer is running, allowing the radio frequency circuit to be turned off during DRX 'Off' durations. This periodic action maintains synchronization reliability while significantly reducing power consumption compared to continuous transmission.
Solution Approach 2:
The patent introduces dynamic adaptation of SRS transmission behavior based on UE mobility state. The network configures different SRS transmission parameters for different mobility scenarios (e.g., high mobility vs. low mobility). For high mobility UEs, more frequent SRS transmission is configured to maintain synchronization, while for low mobility UEs, less frequent transmission suffices. This dynamic configuration optimizes the balance between synchronization reliability and power consumption according to actual mobility conditions.
2Reliability
If the UE transmits uplink timing reference signals frequently to maintain synchronization, then uplink synchronization is improved, but throughput efficiency deteriorates
Solution Approach 1:
The patent implements periodic transmission of uplink timing reference signals (SRS) during DRX 'On' durations rather than continuous transmission. The UE transmits SRS periodically at configured intervals only when the DRX active timer is running, allowing the radio frequency circuit to be turned off during DRX 'Off' durations. This periodic action maintains synchronization reliability while significantly reducing power consumption compared to continuous transmission.
Solution Approach 2:
The patent introduces dynamic adaptation of SRS transmission behavior based on UE mobility state. The network configures different SRS transmission parameters for different mobility scenarios (e.g., high mobility vs. low mobility). For high mobility UEs, more frequent SRS transmission is configured to maintain synchronization, while for low mobility UEs, less frequent transmission suffices. This dynamic configuration optimizes the balance between synchronization reliability and power consumption according to actual mobility conditions.
3Use of energy by moving object
If the UE uses discontinuous reception cycles to conserve power, then battery life is improved, but maintaining uplink synchronization becomes more difficult
Solution Approach 1:
The patent employs an uplink timing alignment timer that is started or restarted when the UE receives a timing advance command from the network. This timer preliminarily establishes a synchronization validity period, allowing the UE to maintain uplink synchronization without continuous transmission. The timer provides a predetermined window of synchronized operation, enabling the UE to enter DRX mode with confidence that synchronization will be maintained for the timer's duration, thus preserving battery life while ensuring synchronization reliability.
Solution Approach 2:
The patent implements a feedback mechanism where the network monitors uplink synchronization status and sends timing advance commands to adjust UE transmission timing. When the uplink timing alignment timer expires or synchronization is detected to be lost, the network can send a new timing advance command to re-synchronize the UE. This feedback loop ensures that even during DRX cycles, the UE maintains reliable uplink synchronization by receiving periodic synchronization corrections from the network.
Data Source
AI summary
A system and method are disclosed for providing uplink timing synchronization during DRX operation in a wireless communication system.