Random Access Response Mapping for Multiple SSB Beams
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently managing random access procedures when multiple synchronization signal blocks (SSBs) are associated with a single random access occasion (RO), leading to increased latency, data interruption, and unnecessary preamble retransmissions due to indistinguishable random access responses (RARs) for different SSB beams.
Innovation Solution
Enhanced RAR configurations are implemented to differentiate RARs based on SSB indices, ensuring that UEs monitor for RARs with specific RA-RNTIs associated with their selected SSB beams, reducing unnecessary preamble retransmissions and latency by indicating the SSB index in the RAR or using it to compute RA-RNTI.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple SSBs are associated with a single RO, then resource utilization is improved, but RACH latency increases due to indistinguishable RARs for different SSB beams
Solution Approach 1:
The patent segments the RAR identification process by introducing SSB index differentiation into the RA-RNTI computation. Each SSB beam is assigned a unique identifier that is incorporated into the RAR detection process, allowing the UE to distinguish between multiple SSB beams sharing the same RO. This segmentation resolves the ambiguity in RAR identification while maintaining the benefit of multiple SSBs per RO for resource utilization.
Solution Approach 2:
The patent applies local quality by making the RAR detection process specific to each SSB beam through unique RA-RNTI identifiers. Instead of a uniform RAR handling approach, the system tailors the RAR detection parameters (RA-RNTI) to the specific SSB beam direction, enabling precise local identification and response for each beam while maintaining the broader framework of multiple SSBs per RO.
2Productivity
If multiple SSBs are associated with a single RO, then system capacity is improved, but data interruption increases due to indistinguishable RARs
Solution Approach 1:
The patent segments the RAR response identification by incorporating SSB-specific RA-RNTI identifiers. This allows the system to maintain high system capacity through multiple SSBs per RO while preventing data interruption by ensuring each UE can reliably identify and process RARs specific to its selected beam, eliminating ambiguity in the random access procedure.
Solution Approach 2:
The patent introduces RA-RNTI as an intermediary identifier that mediates between the multiple SSB beams and the RAR responses. This intermediary mechanism enables the system to handle multiple SSBs simultaneously (maintaining capacity) while providing clear, unambiguous identification for each beam's RAR, thereby preventing data interruption caused by indistinguishable responses.
3Productivity
If multiple SSBs are associated with a single RO, then spectral efficiency is improved, but power consumption increases due to unnecessary preamble retransmissions
Solution Approach 1:
The patent segments the preamble retransmission process by enabling accurate RAR identification through SSB-index-based RA-RNTI differentiation. This allows UEs to successfully complete the random access procedure on the first attempt without unnecessary retransmissions, thereby reducing power consumption while maintaining the spectral efficiency benefits of multiple SSBs per RO.
Solution Approach 2:
The patent implements a feedback mechanism through accurate RAR identification using SSB-specific RA-RNTI identifiers. This feedback system allows the UE to confirm successful preamble reception and processing for the correct SSB beam, eliminating unnecessary retransmissions and reducing power consumption while preserving the high spectral efficiency achieved through multiple SSBs per RO.
Data Source
AI summary
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may transmit, in a synchronization signal block (SSB) beam direction, at least one preamble in a random access channel (RACH) occasion (RO) associated with multiple SSBs. The UE may monitor, in the SSB beam direction, at least one search space for a random access response (RAR) associated with the at least one preamble. Numerous other aspects are described.