Carrier Aggregation Random Access Contention Resolution Binding
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Solution Overview
Problem
In LTE systems, the contention resolution procedure during random access can be erroneously ended due to confusion between uplink grants for Buffer Status Reports, and this issue is exacerbated by carrier aggregation, leading to increased probability of erroneous completion.
Innovation Solution
A method where a User Equipment (UE) performs random access by transmitting a random access preamble through a specific uplink component carrier, receiving a random access response through a corresponding downlink component carrier, and considers the contention resolution successful only when receiving second UL grant information through the same downlink component carrier, ensuring accurate signal analysis and preventing confusion between uplink grants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If carrier aggregation is used to extend bandwidth and improve system capacity, then productivity and data transmission capability are improved, but the probability of confusion between uplink grants from different component carriers increases, leading to erroneous completion of contention resolution procedure and data loss
Solution Approach 1:
The patent introduces a binding relationship as an intermediary mechanism between the random access preamble transmission on uplink component carrier and the corresponding downlink component carrier. This binding relationship acts as a mediator that ensures the UE only processes uplink grants received on the correct downlink component carrier, preventing confusion between grants from different carriers while maintaining the benefits of carrier aggregation for improved system capacity
2Adaptability or versatility
If the UE monitors uplink grants on all downlink component carriers during contention resolution, then adaptability is improved, but measurement precision deteriorates due to inability to distinguish the correct grant corresponding to the transmitted preamble
Solution Approach 1:
The patent segments the monitoring process by establishing a one-to-one binding relationship between the uplink component carrier used for preamble transmission and its corresponding downlink component carrier. This segmentation allows the UE to adaptively monitor multiple downlink component carriers while maintaining precise identification accuracy by only processing grants on the bound downlink carrier, thus resolving the contradiction between adaptability and measurement precision
Data Source
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AI summary
A method for random access to a base station by a user equipment (UE) in a mobile communication system using carrier aggregation in which communication is conducted over a plurality of component carriers, and a terminal for the method are disclosed. When the UE performs a contention-based random access procedure in the mobile communication system to which CA technology is applied, the UE considers an uplink grant signal as a contention resolution message when receiving the uplink grant signal from a eNB only when the uplink grant signal is received through a downlink CC corresponding to an uplink CC used to transmit a random access preamble or a third message, to thereby prevent contention resolution from being erroneously ended.