PRACH Random Access Slot Mapping for Subcarrier Spacing Above 120 kHz

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing communications systems face challenges in configuring RO time-frequency resources when the subcarrier spacing of the PRACH exceeds 120 kHz, as the current configuration tables only support up to 2 PRACH slots per 60kHz slot, limiting the application of higher subcarrier spacings.

Innovation Solution

A new random access method that determines a random access occasion RO time-domain position group, including a transmittable frame number group and slot number groups, to configure RO time-frequency resources for subcarrier spacings greater than 120 kHz, using predefined combinations of slot numbers and ratios based on RACH configuration tables.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the subcarrier spacing of PRACH is increased beyond 120 kHz, then the system can support higher frequency ranges and achieve better spectral efficiency, but the existing configuration tables cannot accommodate the increased number of PRACH slots per reference slot

Engineering Contradiction:
Improvesubcarrier spacingVSAvoidconfiguration table applicability
Core Design Contradiction:
SpeedVSAdaptability or versatility

Solution Approach 1:

The patent segments the slot number indication into two separate fields: a first slot number group indicating reference slots at 60kHz, and a second slot number group indicating actual PRACH slots at higher subcarrier spacings. This segmentation allows the configuration to adapt to different subcarrier spacings by independently specifying slot positions at each level, resolving the contradiction between higher speed and configuration adaptability.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If the number of PRACH slots per reference slot exceeds 2, then higher subcarrier spacings can be supported, but the existing protocol only allows configuration values of 1 or 2 PRACH slots per 60kHz slot

Engineering Contradiction:
Improvesubcarrier spacing supportVSAvoidconfiguration structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent introduces a hierarchical dimension to the slot configuration by establishing a relationship between reference slots at 60kHz and actual PRACH slots at higher subcarrier spacings. The first slot number group operates at the 60kHz reference level, while the second slot number group operates at the actual higher subcarrier spacing level, allowing the system to support more than 2 PRACH slots per reference slot through this dimensional expansion.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If the existing configuration table is used for subcarrier spacing greater than 120 kHz, then implementation simplicity is maintained, but the configuration cannot be applied correctly as the table only supports up to 2 PRACH slots per reference slot

Engineering Contradiction:
Improveconfiguration implementationVSAvoidconfiguration correctness
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent makes the slot configuration dynamic by allowing the number of PRACH slots per reference slot to vary based on the actual subcarrier spacing being used. Instead of being fixed at 1 or 2 as in existing tables, the configuration can now dynamically adjust to support any number of PRACH slots by utilizing the two-level slot number indication mechanism, ensuring both ease of implementation and configuration correctness.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4307803B1Random access method and device, terminal, and storage medium
Publication Date: 2026.02.25 VIVO MOBILE COMM CO LTD
  • EP4307803B1 patent drawingFigure 1~3
  • EP4307803B1 patent drawingFigure 4~10
  • EP4307803B1 patent drawingFigure 11~17

AI summary

The application discloses a random access method and apparatus, a terminal and a storage medium. The method includes: determining, by a terminal, a random access occasion RO time domain position group; selecting a first RO from the RO time domain position group, and calculating a random access radio network temporary identifier RA-RNTI of the first RO; where the RO time domain position group includes at least one of the following: a transmittable frame number group and a first slot number group, and a second slot number group.