Synchronization Signal Block Frequency Mapping for Random Access

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Solution Overview

Problem

When synchronization signal/physical broadcast channel block frequency division multiplexing is applied, existing methods fail to enable the network device to learn the synchronization signal/physical broadcast channel block selected by the terminal device, leading to inefficiencies in random access and increased power consumption.

Innovation Solution

A communication method that involves receiving synchronization signal/physical broadcast channel blocks at different frequency domain positions, determining the corresponding random access channel occasions, and performing random access based on the sending status of the synchronization signal/physical broadcast channel blocks, allowing the network device to identify the selected block.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by stationary object

If synchronization signal/physical broadcast channel block frequency division multiplexing is applied, then power consumption of network device is reduced, but network device cannot learn the synchronization signal/physical broadcast channel block selected by terminal device

Engineering Contradiction:

Improvepower consumption of network deviceVSAvoidnetwork device cannot learn selected block

Core Design Contradiction:

Use of energy by stationary objectVSLoss of information

Solution Approach 1:

The patent segments the synchronization signal/physical broadcast channel blocks into different frequency domain positions (first frequency domain position and second frequency domain position). By dividing the blocks across multiple frequency positions, the network device can receive blocks at different frequencies while still maintaining the ability to identify and learn the selected block through the mapping relationship between frequency domain positions and random access channel occasions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary mapping relationship between synchronization signal/physical broadcast channel blocks at different frequency domain positions and random access channel occasions. This mapping relationship acts as a mediator that enables the network device to infer which block was selected by the terminal device based on the random access channel occasion used, thus resolving the information loss problem while maintaining frequency division multiplexing benefits.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If existing mapping manner is used for frequency division multiplexing, then implementation is simple, but terminal device cannot determine correct random access channel occasion

Engineering Contradiction:

Improveimplementation simplicityVSAvoidterminal device cannot determine correct RACH occasion

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent establishes preliminary mapping relationships between synchronization signal/physical broadcast channel blocks at different frequency domain positions and random access channel occasions before the random access process occurs. These pre-configured mappings enable the terminal device to directly determine the correct random access channel occasion based on the selected block's frequency domain position, eliminating the need for complex real-time determination while ensuring reliability.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If terminal device switches to new frequency domain position, then frequency diversity is improved, but random access delay increases due to repeated SIB1 reception

Engineering Contradiction:

Improvefrequency diversityVSAvoidrandom access delay

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent makes the mapping relationship between frequency domain positions and random access channel occasions universal and applicable across different frequency positions. The same mapping mechanism works for both the first frequency domain position and the second frequency domain position, allowing the terminal device to reuse mapping information when switching frequencies without needing to repeatedly receive and process SIB1, thus maintaining frequency diversity while avoiding random access delay.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12245296B2Communication method and apparatus

Publication Date: 2025.03.04 HUAWEI TECH CO LTD

AI summary

A communication method and device is provided where a network device can learn of a synchronization signal/physical broadcast channel block selected by a terminal device. The method includes receiving, from a network device, a first synchronization signal/physical broadcast channel block located at a first frequency domain position, and receiving, from the network device, a second synchronization signal/physical broadcast channel block located at a second frequency domain position, determining random access channel occasions corresponding to the second frequency domain position, determining, in the random access channel occasions corresponding to the second frequency domain position and based on a sending status of a synchronization signal/physical broadcast channel block located at the second frequency domain position, a random access channel occasion to which the second synchronization signal/physical broadcast channel block is mapped, and performing random access on the random access channel occasion to which the second synchronization signal/physical broadcast channel block is mapped.