Synchronization Sequence Selection for THz Device Discovery and Ranging

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Solution Overview

Problem

The implementation of Terahertz bands in 5G communications faces challenges such as high path loss and antenna development, particularly in defining and establishing effective communication links.

Innovation Solution

The proposed solution involves enhancing antenna performance through techniques like aperture-stacked patch antennas, parasitic elements, and frequency band management, along with synchronization protocols and sequence transmission methods to improve signal transmission and reception in Terahertz bands.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If Terahertz bands are used for 5G communications, then bandwidth and frequency range are increased, but path loss increases and communication link reliability deteriorates

Engineering Contradiction:
Improvedata transmission rateVSAvoidcommunication link reliability
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent segments the Terahertz frequency band into multiple sub-bands and uses multiple synchronization sequences with different cyclic shifts. Each sequence targets specific transparency windows within the band, dividing the challenging wideband transmission into manageable segments that can be individually optimized for reliability while maintaining overall high data rates

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the frequency parameter by selecting synchronization sequences tailored to specific transparency windows within the Terahertz band. By adapting the sequence frequency characteristics to match favorable propagation conditions, the system maintains reliable communication links despite the high path loss inherent in Terahertz frequencies

Inventive Principle:
Principle #35Parameter changes

2Productivity

If synchronization sequences are transmitted continuously, then device discovery speed is improved, but energy consumption increases

Engineering Contradiction:
Improvedevice discovery speedVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic transmission of synchronization sequences with configurable periods and cyclic shifts. Instead of continuous transmission, sequences are sent at periodic intervals, allowing the system to achieve device discovery through multiple periodic opportunities while significantly reducing energy consumption compared to continuous transmission

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent transmits a set of synchronization sequences with different cyclic shifts periodically, where the number of sequences and their periodicity are optimized to achieve sufficient device discovery probability without excessive energy expenditure. The system uses just enough periodic transmissions to ensure discovery while avoiding wasteful continuous transmission

Inventive Principle:
Principle #16Partial or excessive action

3Loss of time

If wideband sequences are transmitted at minimum delay, then synchronization speed is improved, but signal strength deteriorates due to path loss

Engineering Contradiction:
Improvesynchronization timeVSAvoidsignal strength
Core Design Contradiction:
Loss of timeVSPower

Solution Approach 1:

The patent applies local quality by selecting synchronization sequences with specific properties matched to local channel conditions, particularly transparency windows at different distances. The system chooses sequences optimized for the specific propagation conditions and distance range, achieving both fast synchronization and adequate signal strength through localized sequence selection rather than uniform transmission

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4097935B1Transparency window aware sequence selection and transmission procedure for device discovery and range estimation
Publication Date: 2025.09.10 INTERDIGITAL PATENT HOLDINGS INC
  • EP4097935B1 patent drawingFigure 1A
  • EP4097935B1 patent drawingFigure 1B
  • EP4097935B1 patent drawingFigure 1C

AI summary

A method for initial timing synchronization for a WTRU to communicate with a network includes receiving an in-channel narrowband synchronization sequence from the network to enable initial coarse timing synchronization, determining coarse timing offset and a range between a beam source of a network transmitter and the WTRU, selecting a wideband sequence for fine timing synchronization using the estimated range, transmitting the selected wideband sequence for fine timing synchronization during an uplink timing occasion, receiving from the network a transmission of the selected wideband sequence for fine timing synchronization, and establishing fine timing synchronization between the WTRU and the network using the selected sequence.