2-Step Random Access Mapping for SSB-Selected PUSCH Transmission
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Solution Overview
Problem
There is a need for improved methods and apparatuses to perform random access procedures in wireless communication systems, particularly in 6G communication systems, which require enhanced signal transmission distance and coverage due to severe path loss and atmospheric absorption in terahertz bands.
Innovation Solution
A method and apparatus for performing 2-step contention-free random access in wireless communication systems, involving the selection of a synchronization signal block (SSB) with sufficient SS-RSRP, identifying a random access occasion and a physical uplink shared channel (PUSCH) occasion based on configuration information, and transmitting msgA accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If 2-step random access procedure is implemented to reduce latency and improve efficiency, then random access latency and signaling overhead are reduced, but resource allocation complexity and mapping configuration requirements increase
Solution Approach 1:
The patent applies preliminary action by pre-configuring mapping relationships between PRACH occasions and PUSCH occasions before the random access procedure. The base station provides configuration information that includes pre-established mapping rules, allowing the UE to directly determine PUSCH resources without complex real-time allocation decisions, thus reducing latency while managing resource allocation complexity through advance planning
Solution Approach 2:
The patent introduces configuration information as an intermediary that carries mapping relationships between PRACH and PUSCH resources. This intermediary structure simplifies the direct interaction between random access preamble transmission and uplink data transmission by providing a predefined mapping framework, reducing both latency and allocation complexity
2Productivity
If PUSCH resources are shared between 2-step and 4-step random access to improve resource utilization, then resource efficiency increases, but resource allocation complexity and potential conflicts increase
Solution Approach 1:
The patent applies universality by designing PUSCH resources to serve multiple functions - they can be used for both 2-step random access (MsgA) and 4-step random access (Msg3) transmissions. The same PUSCH occasion can accommodate different random access procedures through the configured mapping relationships, improving resource utilization while maintaining clear allocation rules to manage complexity
Solution Approach 2:
The patent uses parameter changes by dynamically adjusting the mapping configuration between PRACH and PUSCH occasions based on the random access type. The configuration information includes parameters that define different mapping relationships for 2-step and 4-step procedures, allowing flexible resource sharing while avoiding conflicts through parameter-based differentiation
3Productivity
If multiple PRACH occasions are mapped to single PUSCH occasion to improve resource efficiency, then resource utilization increases, but uplink timing synchronization difficulty increases
Solution Approach 1:
The patent applies feedback by incorporating uplink timing adjustment information in the random access response. When multiple PRACH occasions are mapped to a single PUSCH occasion, the base station measures the timing of received preambles and provides timing advance commands in the response, enabling the UE to adjust its uplink timing to ensure synchronized transmission on the shared PUSCH resource
Solution Approach 2:
The patent uses preliminary action by pre-establishing the mapping relationship between multiple PRACH occasions and a single PUSCH occasion in the configuration information. This advance configuration allows the system to efficiently aggregate random access attempts from multiple time instances while preparing the timing synchronization mechanism in advance, reducing the difficulty of real-time timing detection and adjustment
Data Source
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AI summary
A method and an apparatus for performing communication in wireless communication system are provided. The method includes receiving random access channel (RACH) configuration information from a base station (BS), in case that a type of a random access is identified as 2-step contention free based on the RACH configuration information, selecting a synchronization signal block (SSB) with synchronization signal- reference signal received power (SS-RSRP) above a configured threshold among SSBs, identifying a random access occasion corresponding to the selected SSB, identifying a physical uplink shared channel (PUSCH) occasion corresponding to a RACH slot of the selected random access occasion from PUSCH occasions configured based on PUSCH resource configuration information included in the RACH configuration information, and performing msgA transmission based on the identified random access occasion and the identified PUSCH occasion.