Two-Step Random Access Preamble Mapping Configuration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The challenge in two-step random access for communication technologies is defining an effective mapping relationship between preambles and uplink data resources and demodulation reference signals (DM-RS) to improve access performance and configuration flexibility.

Innovation Solution

The proposed solution involves the network device implicitly or explicitly configuring the mapping of preambles to uplink data channel resources and DM-RS ports based on configuration information, allowing for flexible configuration and improved random access performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If traditional four-step random access is used, then the random access procedure is well-defined and reliable, but the access speed is slow

Engineering Contradiction:
Improveaccess speedVSAvoidprocedure complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The patent combines the preamble transmission and uplink data transmission into a single msgA, and merges the random access response and uplink grant into msgB. This consolidation reduces the number of interaction steps from four to two, significantly improving access speed while maintaining procedural reliability through well-defined message structures.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent performs preliminary configuration of the mapping relationship between preambles and uplink data resources/DM-RS ports before the random access procedure. This pre-configuration enables the network device to immediately identify the associated PUSCH and DM-RS information upon receiving a preamble, eliminating the need for additional signaling exchanges and accelerating the access process.

Inventive Principle:
Principle #10Preliminary action

2Speed

If two-step random access is implemented, then access speed is improved, but the mapping relationship between preambles and uplink data resources/DM-RS is not clearly defined

Engineering Contradiction:
Improveaccess speedVSAvoidconfiguration clarity
Core Design Contradiction:
SpeedVSEase of operation

Solution Approach 1:

The patent establishes the mapping relationship between preambles and uplink data resources/DM-RS ports in advance through configuration information. This preliminary definition ensures that when a preamble is transmitted in msgA, the network device can immediately determine the associated PUSCH resources and DM-RS ports without ambiguity, maintaining configuration clarity while enabling fast two-step access.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces configuration information as an intermediary that carries the mapping relationship between preambles and uplink data resources/DM-RS ports. This intermediary structure resolves the ambiguity in the two-step procedure by providing a clear reference that both terminal and network devices can use to correctly associate preambles with their corresponding resources and reference signals.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If flexible configuration is provided for preamble mapping, then adaptability to different applications is improved, but system complexity increases

Engineering Contradiction:
Improveconfiguration flexibilityVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent performs preliminary configuration of various mapping relationships between preambles and uplink data resources/DM-RS ports based on different application requirements. By pre-defining these mappings through configuration information, the system achieves high adaptability to different scenarios without increasing runtime complexity, as the configuration is established before the random access procedure begins.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent enables flexible configuration by allowing changes in mapping parameters such as the association between preambles and PUSCH resources, and between preambles and DM-RS ports. These parameter changes can be adapted to different application demands while maintaining a unified configuration framework, achieving versatility without proportionally increasing system complexity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3952566B1Random access method and apparatus
Publication Date: 2025.02.19 FUJITSU LTD
  • EP3952566B1 patent drawingFigure 1~2
  • EP3952566B1 patent drawingFigure 3~4
  • EP3952566B1 patent drawingFigure 5~6

AI summary

A random access method and apparatus. The method includes: transmitting a first random access request at least including a preamble, uplink data and a demodulation reference signal by a terminal equipment to a network device; and receiving a random access response transmitted by the network device; wherein mapping of the preamble to an uplink data channel resource and a demodulation reference signal port is determined according to configuration information or is configured by the network device. Hence, not only a random access performance may be improved, but also sufficient configuration flexibility may be provided.