Uplink BWP Switching for Random Access Synchronization
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Solution Overview
Problem
In wireless communication systems, terminal devices may lose uplink synchronization with base stations as they move, leading to failed reception of uplink information, and existing random access procedures are inefficient in maintaining synchronization.
Innovation Solution
The method involves receiving physical downlink control channel signaling to trigger a random access procedure, switching to a target uplink bandwidth part with a physical random access channel resource, and sending a preamble sequence using that resource to initiate uplink synchronization, thereby reducing the likelihood of base stations failing to receive uplink information from out-of-synchronization terminal devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the terminal device uses existing random access procedures to maintain uplink synchronization, then the synchronization can be restored after loss, but the process is inefficient and increases the likelihood of communication failure
Solution Approach 1:
The patent applies preliminary action by pre-configuring multiple uplink bandwidth parts (BWPs) with different characteristics (e.g., different bandwidths, subcarrier spacings, or power levels) before the terminal device experiences synchronization loss. When synchronization is lost, the base station can immediately trigger a random access procedure on a predetermined target BWP that is optimized for the current channel conditions, rather than requiring the terminal to perform exhaustive BWP selection or trial-and-error access attempts. This pre-configuration enables faster synchronization restoration and improves procedural efficiency.
2Reliability
If the terminal device switches to a target uplink BWP with PRACH resources for random access, then uplink synchronization can be initiated, but additional signaling and processing steps are required
Solution Approach 1:
The base station pre-configures multiple uplink BWPs and associates each with specific PRACH resources and random access parameters before the terminal device needs to perform random access. When uplink synchronization is lost or needs to be established, the base station triggers the random access procedure by signaling a specific target BWP index, and the terminal device directly switches to that pre-configured BWP and uses the associated PRACH resources. This eliminates the need for the terminal to perform complex BWP selection, parameter negotiation, or multiple access attempts, thereby reducing signaling overhead and processing complexity while ensuring reliable synchronization establishment.
Data Source
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AI summary
This application discloses a resource configuration method, an apparatus, and a system, and relates to the field of communications technologies. The method includes: receiving PDCCH signaling; switching to a target uplink BWP; and sending a preamble sequence by using a PRACH resource included in the target uplink BWP, where the PDCCH signaling is used to trigger a random access procedure. By introducing the PDCCH signaling, the foregoing technical solution helps reduce a possibility that a base station cannot receive uplink information sent by a terminal device after the terminal device is out-of-synchronization with the base station in an uplink direction.