Two-Step Random Access PUSCH Resource Determination
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Solution Overview
Problem
In two-step random access procedures for wireless communication networks, determining the resource for Physical Uplink Shared Channel (PUSCH) is challenging as there is no explicit Message 2 to provide the necessary resource allocation, unlike in the four-step procedure.
Innovation Solution
A method and system for a terminal device and network device to determine the PUSCH resource based on the random access occasion and preamble, using mappings and signaling to allocate time and frequency domain resources, allowing proper transmission and reception of PUSCH messages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a two-step random access procedure is used to minimize channel accesses, then the number of channel accesses is reduced, but the resource allocation for PUSCH becomes more complex and difficult to determine
Solution Approach 1:
The patent applies preliminary action by pre-configuring mapping relationships between PRACH resources and PUSCH resources before the random access procedure begins. The terminal device determines PUSCH resources based on pre-established mappings with PRACH occasions and preambles, eliminating the need for explicit resource allocation in Message 2 and simplifying the two-step procedure while maintaining efficient resource allocation
Solution Approach 2:
The patent uses the PRACH occasion and preamble as intermediary elements to bridge the gap between random access initiation and PUSCH resource allocation. By establishing mapping relationships where PRACH resources serve as intermediaries to determine PUSCH resources, the system enables implicit resource allocation without requiring additional signaling messages, thus resolving the complexity issue while maintaining the two-step procedure's efficiency
2Ease of operation
If explicit resource allocation is provided in Message 2 as in four-step procedure, then resource allocation is straightforward, but the procedure requires more signaling messages and increases channel accesses
Solution Approach 1:
The patent merges the resource allocation function into the existing PRACH occasion and preamble selection process. By combining the random access initiation (PRACH) with the resource indication mechanism, the system eliminates the need for separate Message 2 resource allocation while maintaining clear and straightforward resource determination through pre-configured mappings between PRACH and PUSCH resources
Solution Approach 2:
The patent enables self-service by allowing the terminal device to autonomously determine PUSCH resources based on its own PRACH occasion and preamble selection. The terminal uses pre-configured mapping relationships to self-determine the corresponding PUSCH resources without requiring explicit allocation from the network, thus eliminating Message 2 while maintaining operational simplicity
Data Source
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AI summary
The present disclosure provides a method (200) in a terminal device. The method (200) includes: determining (210) a preamble to be transmitted to a network device on a random access occasion; determining (220) a Physical Uplink Shared Channel, PUSCH, resource for transmitting a PUSCH based on the random access occasion or on the random access occasion and the preamble; and transmitting (230) to the network device the preamble on the random access occasion and the PUSCH on the PUSCH resource, in a random access message.