NR Terminal MsgA Resource Mapping When PRACH Occasions Are Invalid
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Solution Overview
Problem
In the contention-based random access procedure of the NR wireless communication system, the two-step random access procedure faces issues when PRACH transmission occasions overlap with downlink or SSB, leading to invalidation of resources and complexity in determining appropriate PUSCH transmission occasions.
Innovation Solution
The method involves determining resource allocation and correspondence between MsgA-PRACH and MsgA-PUSCH occasions by excluding or invalidating overlapping or invalid occasions, ensuring no overlap in the time domain, and prioritizing or adjusting transmission slots based on conditions such as frequency range and beamforming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If PRACH transmission occasions are associated with PUSCH transmission occasions in the two-step random access procedure, then the random access efficiency is improved, but the system complexity increases when determining valid transmission occasions due to overlap issues with downlink or SSB
Solution Approach 1:
The patent applies preliminary action by pre-determining the association relationship between PRACH occasions and PUSCH occasions before the random access procedure occurs. The base station configures and indicates to the terminal which PUSCH occasions are associated with which PRACH occasions, allowing the terminal to proactively identify valid transmission resources without complex real-time determination during the random access process.
Solution Approach 2:
The patent uses the base station as an intermediary to resolve the contradiction. The base station receives the random access preamble from the terminal, determines the appropriate PUSCH transmission occasion based on the association relationship, and provides uplink grant information to the terminal. This intermediary approach simplifies the terminal's decision-making process while maintaining efficient resource utilization.
2Quantity of substance
If PRACH transmission occasions overlap with downlink or SSB in the time domain, then the time resource utilization is maximized, but the PRACH transmission occasions become invalid and cannot be used
Solution Approach 1:
The patent applies the taking out principle by extracting and identifying the valid PRACH transmission occasions from the set of all configured PRACH occasions. When overlap with downlink or SSB is detected, the system excludes (takes out) the invalid overlapping occasions from consideration, leaving only the valid non-overlapping occasions for random access transmission.
Solution Approach 2:
The patent changes the parameter of occasion validity based on the overlap condition. The system dynamically determines whether a PRACH occasion is valid or invalid by checking its time domain overlap with downlink or SSB resources. This parameter change allows the system to adaptively select valid transmission occasions while maximizing overall resource utilization.
3Adaptability or versatility
If the relationship between PRACH transmission occasions and PUSCH transmission occasions is changed when PRACH occasions are invalid, then the random access procedure can continue, but the resource allocation complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-establishing the association relationship between PRACH occasions and PUSCH occasions. When a PRACH occasion is found to be invalid due to overlap, the terminal can immediately refer to the pre-configured association to identify the corresponding valid PUSCH occasion, avoiding complex real-time resource allocation decisions and maintaining procedure continuity.
Data Source
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AI summary
A terminal includes a control unit configured to identify a first transmission occasion to transmit a message used in a two-step random access procedure via a physical random access channel and a second transmission occasion to transmit the message via a physical uplink shared channel, and a transmission unit configured to transmit the message using the first transmission occasion and the second transmission occasion, wherein the control unit is configured to change a method of identifying the second transmission occasion when the first transmission occasion is invalidated.