PRACH Transmission and Reception With Unambiguous RO Grouping

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Solution Overview

Problem

Conventional schemes do not provide a clear definition for determining an RO group for multiple PRACH transmissions, leading to ambiguity in terminal/base station operations regarding which ROs to use for multiple PRACH transmissions when multiple ROs are frequency division multiplexed at a specific time instance.

Innovation Solution

The method involves defining an RO group for multiple PRACH transmissions, where a plurality of ROs are related to the same synchronization signal/physical broadcast channel block index, with the first RO being the starting point, and subsequent ROs are determined in ascending order of time resource indexes based on the frequency resource index of the first RO.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If multiple ROs are frequency division multiplexed at a specific time instance, then the capacity for PRACH transmissions is improved, but ambiguity arises in determining the RO group for multiple PRACH transmissions

Engineering Contradiction:
Improvenumber of PRACH transmissionsVSAvoidambiguity in RO group determination
Core Design Contradiction:
Quantity of substanceVSLoss of information

Solution Approach 1:

The patent segments the set of multiple PRACH occasions into distinct RO groups, where each RO group contains a specific number of ROs (e.g., 2, 4, or 8 ROs per group). This segmentation allows the system to maintain multiple FDMed ROs while providing clear structure for determining which ROs belong together for multiple transmissions, thereby resolving the ambiguity without reducing the total number of available transmission opportunities.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces new parameters including the RO group index, the number of ROs per RO group, and the number of RO groups. These parameters provide a systematic framework for identifying and managing multiple PRACH occasions, transforming the ambiguous situation into a well-defined parameterized system where each RO can be uniquely identified within its group context.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If no clear definition is provided for RO group determination, then flexibility in PRACH configuration is maintained, but operational ambiguity between terminal and base station increases

Engineering Contradiction:
ImprovePRACH configuration flexibilityVSAvoidoperational consistency
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent creates a universal RO group determination mechanism that works across different PRACH configurations and scenarios. The RO group concept provides a multi-functional framework that can accommodate various numbers of FDMed ROs (2, 4, or 8) while maintaining consistent operational rules, thereby ensuring both flexibility and reliability simultaneously.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

By introducing configurable parameters such as the number of ROs per RO group and the number of RO groups, the system maintains adaptability to different deployment scenarios while establishing clear operational rules. These parameters allow the network to configure appropriate RO group structures based on specific requirements while ensuring unambiguous terminal and base station operations.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4598240A1Method and device for transmission and reception of random access channel in wireless communication system
Publication Date: 2025.08.06 LG ELECTRONICS INC
  • EP4598240A1 patent drawingFigure 1~2
  • EP4598240A1 patent drawingFigure 3~4
  • EP4598240A1 patent drawingFigure 5(a)~5(b)

AI summary

A method performed by a terminal, according to an embodiment of the present disclosure, comprises the steps of: transmitting a PRACH on the basis of at least one RO; and receiving an RAR. The at least one RO comprises a plurality of ROs belonging to an RO group for multi-transmission of the PRACH. The plurality of ROs comprises i) a first RO and ii) at least one second RO. The at least one second RO is characterized by comprising ROs determined in the ascending order of time resource indexes after the first RO, on the basis of a frequency resource index related to the first RO.