Carrier Aggregation Timing Advance Adjustments
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Solution Overview
Problem
Wireless network congestion in licensed spectrum due to increased mobile device usage, particularly in high-density areas, is exacerbated by bandwidth limitations when multiple users access high-bandwidth applications, and existing carrier aggregation techniques struggle with timing differences across different frequency carriers in Orthogonal Frequency Division Multiple Access (OFDMA) systems.
Innovation Solution
Implementing a method for performing separate timing advances for each component carrier in carrier aggregation systems, using techniques such as the 11-bit timing advance command and MAC Control Elements with 6-bit or extended timing advance commands, to adjust and maintain synchronization across multiple carriers, allowing for more efficient data transmission and reception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If carrier aggregation is used to increase bandwidth, then data throughput is improved, but timing synchronization deteriorates due to different propagation paths of different carriers
Solution Approach 1:
The patent divides the timing advance adjustment into separate components for each component carrier. Instead of using a single timing advance value for all carriers, the system performs independent timing advance adjustments for each carrier based on its specific propagation characteristics, thereby maintaining synchronization reliability while preserving the bandwidth benefits of carrier aggregation
Solution Approach 2:
The patent applies different timing advance values to different component carriers based on their local propagation conditions. Each carrier receives a customized timing advance adjustment tailored to its specific path characteristics, ensuring optimal synchronization for each carrier while maintaining the overall carrier aggregation system's high data throughput capability
2Reliability
If separate timing advance adjustments are performed for each component carrier, then timing synchronization is improved, but system complexity increases
Solution Approach 1:
The patent performs timing advance adjustments during the random access procedure and initial connection setup phase. By establishing the appropriate timing advance values for each component carrier early in the connection establishment process, the system avoids the need for continuous complex adjustments during data transmission, thereby reducing overall system complexity while maintaining synchronization reliability
Solution Approach 2:
The patent implements a feedback mechanism where the base station measures the timing of received signals from each component carrier and provides timing advance commands to the user equipment. This closed-loop feedback system automatically maintains synchronization without requiring complex manual configuration or continuous monitoring, simplifying the system while ensuring reliable timing alignment across all carriers
Data Source
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AI summary
Technology for performing multiple timing advances in a carrier aggregation communication system is disclosed. A method comprises communicating a random access preamble from a UE to an eNodeB via a PCell associated with a selected component carrier of the carrier aggregation. A Random Access Response (RAR) is received at the UE from the eNodeB for the PCell. The RAR contains a timing advance adjustment instructing the UE to adjust a timing of a PCell wireless communication. A request is received at the UE to adjust a timing of an SCell communication. A random access preamble is communicated to the UE via the SCell. An RAR is received at the UE from the eNodeB for the SCell to adjust a timing advance of the SCell wireless communication.