Uplink Synchronization for Component Carriers via Base Station TA Calculation
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Solution Overview
Problem
In LTE-A systems, achieving uplink synchronization with newly configured component carriers (CCs) is challenging when different CCs have distinct timing advance (TA) values, especially when CCs are configured on different repeaters or frequencies, or when communicating with non-collaborated access points.
Innovation Solution
A method for uplink synchronization processing involves receiving an uplink synchronization indication message from the base station, sending synchronization signaling, and applying a TA value calculated using a formula (TA new = TA reference + TA - M × Ts) to newly configured CCs, where TA reference is a reference TA value, M is a preset empirical value, and Ts is a timing parameter, to ensure synchronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the base station configures multiple component carriers (CCs) with different TA values, then the system can support wider bandwidth and higher data rates through carrier aggregation, but the complexity of achieving uplink synchronization with newly configured CCs increases significantly
Solution Approach 1:
The base station performs preliminary calculations of the TA value for newly configured CCs using the formula TA new = TA reference + TA - M × Ts, based on timing difference measurements from synchronization signals. This preliminary action allows the UE to directly apply the pre-calculated TA value without performing complex RACH procedures, thus resolving the synchronization complexity issue while maintaining high data rates through carrier aggregation
Solution Approach 2:
The patent introduces an intermediary mechanism where the base station acts as a mediator that calculates and provides TA values to the UE for newly configured CCs. Instead of the UE performing complex autonomous synchronization, the base station intermediates by measuring timing differences and computing appropriate TA values, thereby simplifying the UE's synchronization task while enabling support for multiple CCs with different TA values
2Reliability
If the UE performs random access channel (RACH) procedures for each newly configured CC, then uplink synchronization can be achieved, but the time and downlink radio resources required increase
Solution Approach 1:
The base station performs self-service by autonomously measuring the timing difference of synchronization signals from the UE on newly configured CCs and calculating the appropriate TA value using the formula TA new = TA reference + TA - M × Ts. This self-service approach eliminates the need for the UE to perform time-consuming RACH procedures, thereby reducing synchronization time while maintaining synchronization accuracy through the base station's precise measurements and calculations
Data Source
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AI summary
An uplink synchronization processing method, a User Equipment (UE), and a base station are provided. The method includes: receiving an uplink synchronization indication message sent by a base station, wherein the uplink synchronization indication message carries identification information of one or multiple newly configured component carriers CCs; and performing the uplink synchronization on the one or multiple newly configured CCs, if knowing the one or multiple newly configured CCs and a currently used CC do not belong to the same CC group according to the identification information of the one or multiple newly configured CCs, wherein the CC group is a group of CCs which can use the same time advanced TA value.