MsgA PUSCH Frequency Hopping in 2-Step Random Access

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Solution Overview

Problem

Existing wireless communication systems in the NR system face challenges in efficiently configuring frequency hopping for the initial transmission of msgA PUSCH in the 2-step random access procedure, particularly due to the lack of scheduling signals for msgA PUSCH and the need for improved methods to enable or disable frequency hopping.

Innovation Solution

The proposed solution involves configuring frequency hopping for msgA PUSCH through RRC signaling, including cell-specific and UE-specific messages, with parameters such as frequency offset, hopping type, and redundancy version, based on PRACH configuration, PUSCH configuration, and system characteristics like FDD/TDD and frequency bands, to ensure proper frequency hopping for msgA PUSCH transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If frequency hopping is enabled for msgA PUSCH transmission, then interference management and transmission reliability are improved, but the complexity of configuring and controlling frequency hopping parameters increases

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidconfiguration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by configuring frequency hopping parameters in advance through RRC signaling before the actual PUSCH transmission. The base station pre-configures hopping patterns, offsets, and timing information, allowing the terminal to execute frequency hopping automatically during transmission without real-time complex calculations, thus improving reliability while managing configuration complexity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback mechanisms where the base station monitors the frequency hopping execution and transmission quality, and adjusts parameters accordingly. The network can detect transmission status and modify frequency hopping configurations based on actual channel conditions, creating a closed-loop system that improves reliability while adapting to changing network conditions

Inventive Principle:
Principle #23Feedback

2Reliability

If frequency hopping parameters are configured through RRC signaling, then proper frequency hopping control is achieved, but the signaling overhead and configuration time increase

Engineering Contradiction:
Improvefrequency hopping controlVSAvoidconfiguration time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-configuring frequency hopping parameters through RRC signaling during network setup or reconfiguration phases. Once configured, these parameters can be reused for multiple PUSCH transmissions without repeated signaling, reducing the time overhead of frequency hopping control while maintaining reliable operation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent makes RRC signaling multi-functional by using the same configuration framework for both initial access and subsequent communications. The frequency hopping configuration mechanism serves multiple purposes including msgA PUSCH transmission, retransmissions, and different channel conditions, reducing the need for separate signaling for each scenario

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

3Ease of operation

If frequency hopping is disabled when frequency offset is not configured, then transmission simplicity is maintained, but interference management capability is reduced

Engineering Contradiction:
Improvetransmission simplicityVSAvoidinterference
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the frequency offset parameter based on network conditions and configuration availability. When frequency offset is configured, the system switches to frequency hopping mode to improve interference management. When frequency offset is not configured, the system maintains simple transmission mode, creating a flexible adaptation that balances simplicity and interference protection

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3997938B1Methods, terminal device and base station for random access procedure
Publication Date: 2026.03.18 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3997938B1 patent drawingFigure 1~2
  • EP3997938B1 patent drawingFigure 3
  • EP3997938B1 patent drawingFigure 4~5

AI summary

Methods, a terminal device and a base station for random access procedure are disclosed. According to an embodiment, the terminal device determines a frequency hopping configuration for transmission of one or more physical uplink shared channels (PUSCHs) in a request message for random access. The terminal device transmits the one or more PUSCHs in the request message based on the frequency hopping configuration. The request message at least comprises a physical random access channel (PRACH) preamble and the one or more PUSCHs.