FDRA Field Truncation for Random Access in Shared Spectrum

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Solution Overview

Problem

Current wireless communication systems face inefficiencies in performing random access procedures, particularly in unlicensed bands, due to challenges in channel access and resource allocation, leading to increased latency and reduced resource efficiency.

Innovation Solution

The method involves optimizing the FDRA field in the PUSCH for shared spectrum channel access by truncating or padding bits based on the number of PRBs in a BWP, allowing for more efficient random access procedures by differentiating the operation based on the number of PRBs, thereby improving channel access efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the FDRA field is truncated to its X LSBs based on the number of PRBs in the BWP, then the random access procedure efficiency is improved, but the device complexity increases due to the need to determine X and Y values

Engineering Contradiction:
Improverandom access procedure efficiencyVSAvoidFDRA field processing complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the FDRA field length based on the number of PRBs in the BWP. When the number of PRBs is less than or equal to 90, the FDRA field is truncated to X LSBs; when greater than 90, it is padded to Y MSBs. This parameter adaptation optimizes the balance between information completeness and processing efficiency, resolving the contradiction between random access efficiency and device complexity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the FDRA field is padded with Y MSBs when the number of PRBs is greater than 90, then the information completeness is improved, but the transmission time increases

Engineering Contradiction:
Improveinformation completenessVSAvoidtransmission time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies partial action by selectively padding the FDRA field only when necessary (when the number of PRBs exceeds 90). The padding with Y MSBs provides the necessary information completeness for larger PRB configurations without unnecessarily increasing transmission time for smaller configurations. This conditional approach optimizes the balance between information completeness and transmission efficiency.

Inventive Principle:
Principle #16Partial or excessive action

3Ease of operation

If the random access procedure uses conventional channel access methods in unlicensed bands, then the channel access is simplified, but the resource utilization efficiency decreases

Engineering Contradiction:
Improvechannel access simplicityVSAvoidresource utilization efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent applies dynamics by making the channel access procedure adaptive to different BWP configurations. The FDRA field processing dynamically adjusts based on the number of PRBs, allowing the system to optimize resource allocation efficiency for each specific configuration while maintaining operational simplicity through standardized processing rules. This dynamic adaptation resolves the contradiction between operational simplicity and resource utilization efficiency.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4040909B1Method and apparatus for transmitting/receiving signals in wireless communication system
Publication Date: 2024.11.06 LG ELECTRONICS INC
  • EP4040909B1 patent drawingFigure 1
  • EP4040909B1 patent drawingFigure 2
  • EP4040909B1 patent drawingFigure 3

AI summary

A method and an apparatus for transmitting/receiving signals in a wireless communication system, according to one embodiment of the present invention, perform a 2- or 4-step random access process in a shared spectrum. In a method for interpreting an FDRA field for PU SCH transmissions corresponding to an RAR in a 4-step random access process or a fallback RAR in a 2-step random access process, the X LSB of the FDRA field is truncated, or the FDRA field is padded with a Y MSB, on the basis of whether interlace allocation for a PUSCH for access to a shared spectrum channel is provided, and the FDRA field is interpreted as the FDRA field of downlink control information (DCI) format 0_0.