RACH-SSB Association for Carrier Aggregation Beam Identification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems, base stations struggle to determine which beams are used by user equipment during carrier aggregation, leading to improper beam-formed transmissions and reduced benefits from carrier aggregation.
Innovation Solution
A method where a base station connects to a user equipment via a first cell, configures a signaling radio bearer, and transmits a radio resource control message to associate random access channel resources with synchronization signal blocks or channel state information reference signals, allowing for proper communication via secondary cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a base station configures a second cell for carrier aggregation without RACH association configuration, then the carrier aggregation can be established, but the base station cannot determine which beams are used by the user equipment, leading to improper beam-formed transmissions
Solution Approach 1:
The patent applies preliminary action by configuring the RACH-SSB association configuration in advance through RRC signaling before the user equipment performs random access. This pre-configuration establishes the mapping relationship between RACH resources and SSBs/CSI-RS, enabling the base station to later determine which beams the user equipment is using based on the RACH resource selected, thus preventing the loss of beam identification information while maintaining carrier aggregation capability
Solution Approach 2:
The patent implements feedback through the random access procedure where the user equipment selects a specific RACH resource based on the RACH-SSB association configuration and transmits the RA preamble. The base station receives this preamble on the specific RACH resource, which provides feedback information about which SSB or CSI-RS the user equipment detected, thereby recovering the beam identification information that would otherwise be lost
2Reliability
If the base station configures RACH resources with association configuration to SSB or CSI-RS, then beam-formed transmissions can be performed properly, but the signaling overhead increases
Solution Approach 1:
The patent applies segmentation by dividing the beam management process into distinct components: the RACH-SSB association configuration is segmented and transmitted through dedicated RRC signaling, while the actual beam selection and random access proceed separately. This segmentation allows the association configuration to be established once and reused, reducing repeated signaling overhead while maintaining reliable beam-formed transmissions
Solution Approach 2:
The patent uses copying by reusing the RACH-SSB association configuration for multiple random access procedures. Once the association between RACH resources and SSBs/CSI-RS is established through RRC signaling, this configuration is copied and applied across different carrier aggregation scenarios, reducing the need for repeated configuration signaling while maintaining transmission reliability
Data Source
AI summary
A base station connects to a communication device via a first cell, and transmits a radio resource control (RRC) message to the communication device via the first cell, wherein the RRC message configures a second cell to the communication device for a carrier aggregation and comprises a random access channel (RACH) configuration for the communication device to perform a random access (RA) to the second cell, the RACH configuration configures at least one RACH resource, and the RRC message configures an association configuration associating the at least one RACH resource with a first synchronization signal block or with a first channel state information reference signal transmitted via the second cell; receiving a RA preamble from the communication device via the second cell according to the at least one RACH resource.