5G Unlicensed-Band SSB Indexing for Reliable Synchronization
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Solution Overview
Problem
Existing methods struggle to effectively transmit and receive synchronization signals in unlicensed bands, limiting opportunities for channel access and synchronization in 5G communication systems.
Innovation Solution
A method and apparatus for a base station and terminal to identify an unlicensed band's availability and transmit synchronization signals using a first and second SSB index, enabling time and frequency synchronization through a modulo operation, and providing PRACH resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If synchronization signals are transmitted in unlicensed bands using conventional methods, then channel access opportunities are limited, but transmission reliability and synchronization accuracy deteriorate
Solution Approach 1:
The synchronization signal transmission is segmented into multiple SSBs (Synchronization Signal Blocks) with different indices. The first SSB index is used for time synchronization while the second SSB index (obtained through modulo operation) is used for frequency synchronization and PRACH resource identification. This segmentation allows independent optimization of different synchronization functions and increases transmission opportunities.
Solution Approach 2:
The patent introduces dynamic selection of SSB indices based on channel conditions and availability. The base station dynamically determines which SSB to transmit by performing modulo operation on the first SSB index, allowing flexible adaptation to changing unlicensed band conditions while maintaining reliable synchronization.
2Measurement precision
If multiple SSB indices are used for synchronization, then time and frequency synchronization accuracy improve, but system complexity increases
Solution Approach 1:
The patent pre-establishes the mapping relationship between the first and second SSB indices through modulo operation before actual transmission. This preliminary configuration allows the terminal to efficiently determine the appropriate SSB index without complex real-time calculations, reducing system complexity while maintaining high synchronization accuracy.
3Productivity
If synchronization signals are transmitted more frequently in unlicensed bands, then channel access opportunities increase, but energy consumption increases
Solution Approach 1:
The patent implements periodic transmission of synchronization signals using SSBs with different indices. By cycling through multiple SSB indices in a structured manner (using modulo operation), the system increases transmission opportunities while maintaining energy efficiency through predictable, periodic patterns rather than continuous transmission.
Data Source
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AI summary
The disclosure relates to a communication method and system for converging a 5th-generation (5G) communication system for supporting higher data rates beyond a 4th-generation (4G) system with a technology for Internet of things (IoT). The disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart homes, smart buildings, smart cities, smart cars, connected cars, health care, digital education, smart retail, and security and safety services. A method and an apparatus for transmitting or receiving a synchronization signal block in a wireless communication system which operates in an unlicensed band are provided. The method includes a method for configuring a synchronization signal block time resource and index by a node which is to transmit a synchronization signal block in an unlicensed band, and a method for determining a synchronization signal block index and acquiring time synchronization by a node which receives a transmitted synchronization signal block.