RAR Indications for Unlicensed Uplink Access and Timing
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Solution Overview
Problem
There is currently no reasonable design solution for Random Access Response (RAR) in a random access procedure on an unlicensed spectrum, leading to challenges in determining the channel access mode and time domain position for uplink transmissions by User Equipment (UE).
Innovation Solution
The RAR message is utilized to provide first and second indication information for determining the target channel access mode and time domain position of the uplink transmission, with the first indication information indicating the channel access mode and the second indication information determining the time domain position, using redundant bits in the TA command field or higher layer signaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the RAR message is used to indicate uplink resources in a random access procedure on an unlicensed spectrum, then the UE can perform random access, but there is no reasonable design solution for indicating the channel access mode and time domain position
Solution Approach 1:
The patent applies parameter changes by reusing existing fields in the RAR message (such as the TA command field, frequency domain resource assignment field, or time domain resource assignment field) to carry additional indication information for channel access mode and time domain position. This allows the RAR message to convey multiple pieces of information by changing how existing parameters are interpreted or combined, without adding new message structures.
Solution Approach 2:
The patent implements universality by making existing RAR message fields serve multiple functions. For example, the TA command field not only provides timing advance information but also indicates the channel access mode for uplink transmission. This multi-functionality reduces the need for separate indication fields and simplifies the overall message structure while enabling random access on unlicensed spectrum.
2Productivity
If indication information is added to the RAR message to specify channel access mode and time domain position, then the random access procedure can be completed, but the message size and processing complexity increase
Solution Approach 1:
The patent applies merging by combining multiple indication functions into existing RAR message fields. Instead of adding separate fields for channel access mode indication and time domain position indication, the patent merges these indications into fields that already exist in the message structure, such as combining timing advance information with channel access mode indication in the TA command field.
Solution Approach 2:
The patent uses parameter changes to enable existing fields to carry additional meaning. For example, certain bits in existing fields are reinterpreted or repurposed to indicate channel access mode or time domain position, allowing the message to convey more information without increasing its overall size.
3Measurement precision
If the RAR message carries both channel access mode indication and time domain position indication, then the UE can determine transmission parameters accurately, but the message structure becomes more complex
Solution Approach 1:
The patent applies universality by designing existing RAR message fields to serve multiple purposes. For instance, the frequency domain resource assignment field not only indicates frequency resources but also provides time domain position information. This multi-functionality allows accurate transmission parameter determination while maintaining a relatively simple message structure.
Solution Approach 2:
The patent merges multiple indication functions into unified field interpretations. By combining channel access mode indication and time domain position indication within existing field structures, the patent achieves accurate parameter determination without creating separate dedicated fields for each indication, thus avoiding excessive structural complexity.
Data Source
AI summary
An information indication method and apparatus, a device, and a storage medium, relating to the technical field of communications. The method comprises: receiving a random access response (RAR) message (301); and obtaining at least one of first indication information and second indication information from the RAR message, wherein the first indication information is used for determining a target channel access approach corresponding to the target uplink transmission; the second indication information is used for determining the time domain position of the target uplink transmission (302). The target channel access approach and the time domain position corresponding to the target uplink transmission can be determined according to the RAR message, so that a UE can realize random access on an unlicensed spectrum.