NR SSB Transmission via Channel Sensing in Unlicensed Spectrum

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Solution Overview

Problem

In New Radio (NR) systems using unlicensed spectrum, network devices face challenges in effectively transmitting Synchronization signal/BCH blocks (SSB) due to the need for channel availability, which limits resource utilization and increases complexity in blind detection for terminal devices.

Innovation Solution

A method where a network device senses multiple time-frequency resources within a period to determine available channels and prioritizes transmission on the first available resource, sending the SSB through this resource, and indicates transmission information to the terminal device to reduce unnecessary detection and improve resource efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the network device sends the SSB on multiple time-frequency resources to increase transmission opportunities, then the reliability of SSB transmission is improved, but the resource overhead increases and terminal device complexity increases

Engineering Contradiction:
ImproveSSB transmission reliabilityVSAvoidterminal device blind detection complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the SSB transmission process by dividing multiple candidate time-frequency resources into distinct groups, where the first group contains the first time-frequency resource and the second group contains the second time-frequency resource. The network device performs channel sensing separately for each group and transmits the SSB only in groups where the channel is available, thereby reducing unnecessary transmissions and lowering terminal device complexity while maintaining transmission reliability.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the network device performs channel sensing on multiple time-frequency resources to ensure transmission availability, then the SSB transmission success rate is improved, but the resource utilization efficiency deteriorates

Engineering Contradiction:
ImproveSSB transmission success rateVSAvoidresource utilization efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies preliminary action by having the network device perform channel sensing on the first time-frequency resource before transmission. Based on the sensing result, the network device determines whether to transmit the SSB on the first resource or preemptively switch to the second time-frequency resource. This advance channel assessment ensures transmission success while avoiding wasteful sensing and transmission attempts on unavailable channels, thereby improving resource utilization efficiency.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If the network device configures multiple candidate time-frequency resources for SSB transmission, then the transmission flexibility is improved, but the resource overhead increases

Engineering Contradiction:
Improvetransmission flexibilityVSAvoidresource overhead
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent applies local quality by configuring different numbers of candidate time-frequency resources in different resource groups based on local channel conditions and transmission requirements. The first group of time-frequency resources may have a different configuration than the second group, allowing the system to optimize resource allocation locally rather than uniformly across all resources, thereby reducing overall resource overhead while maintaining transmission flexibility.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3780745B1Signal transmission method, network device, and terminal device
Publication Date: 2023.05.03 GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP LTD
  • EP3780745B1 patent drawingFigure 1~2
  • EP3780745B1 patent drawingFigure 3~5
  • EP3780745B1 patent drawingFigure 6~7

AI summary

Embodiments of the present application provide a signal transmission method, a network device, and a terminal device. The method comprises: a network device detecting a first carrier, and determining, according to the detection result, a time-frequency resource granted a channel license from M1 time-frequency resources, wherein the M1 time-frequency resources are time-frequency resources that the network device configures for a first period on the first carrier and are available to transmit a first synchronization signal/PBCH block (SSB, or SS/PBCH block), wherein M1 is a positive integer, and M1 ≥ 2; and the network device transmitting the first SSB to a terminal device via the first time-frequency resource.