GNSS-Assisted SSB Timing for Faster NTN Cell Search

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Solution Overview

Problem

In non-terrestrial networks, the power budget constraints of satellites limit the number of simultaneously active downlink beams, leading to increased UE power consumption and hardware complexity during initial cell search due to longer SSB periodicities, which are not aligned with time division schemes.

Innovation Solution

Implementing GNSS-assisted sparse SSB transmission with aligned transmit timing to reduce power consumption and hardware complexity by allowing longer SSB periodicity without increasing UE search time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If SSB periodicity is increased to reduce satellite transmission power consumption, then satellite power usage is reduced, but UE initial cell search time increases

Engineering Contradiction:

Improvesatellite transmission powerVSAvoidUE initial cell search time

Core Design Contradiction:

Loss of energyVSLoss of time

Solution Approach 1:

The patent applies preliminary action by providing the UE with advance information about the search window start time through reference time indication and offset signaling. This allows the UE to prepare and start monitoring at the precise moment when SSB transmission begins, eliminating the need for prolonged search periods even when SSB periodicity is extended.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary mechanism by using reference time information and time offset signaling as a mediator between the satellite's SSB transmission timing and the UE's search window timing. This intermediary signaling enables precise synchronization without requiring the UE to perform extensive blind searches, thus resolving the contradiction between extended periodicity and search time.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Loss of energy

If SSB periodicity is increased to conserve satellite power, then satellite power consumption is reduced, but UE hardware complexity increases

Engineering Contradiction:

Improvesatellite power consumptionVSAvoidUE hardware complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

By providing reference time and offset information in advance, the UE can configure its search window parameters beforehand rather than requiring complex real-time processing and extended monitoring hardware. This preliminary signaling simplifies the hardware requirements while still supporting extended SSB periodicity.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If SSB search window duration is extended to cover longer periodicity, then SSB detection reliability is improved, but UE power consumption during search increases

Engineering Contradiction:

ImproveSSB detection reliabilityVSAvoidUE power consumption during search

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies preliminary action by signaling the search window start time and duration to the UE in advance through reference time indication. This allows the UE to concentrate its power consumption into a precisely defined, shortened search window rather than extending monitoring over the entire SSB periodicity, thus maintaining detection reliability while reducing overall power consumption.

Inventive Principle:

Principle #10Preliminary action

4Loss of energy

If satellite transmits SSB at longer periodicity to save power, then satellite power budget is optimized, but alignment with time division scheme is lost

Engineering Contradiction:

Improvesatellite power budget efficiencyVSAvoidtime division scheme alignment

Core Design Contradiction:

Loss of energyVSStability of the object's composition

Solution Approach 1:

The patent applies dynamics by making the search window configuration adaptive and configurable based on the actual SSB periodicity. The network can dynamically adjust the search window parameters (start time, duration) through signaling to match the extended SSB periodicity while maintaining proper alignment with the time division scheme, allowing the system to flexibly accommodate longer periodicities without losing synchronization structure.

Inventive Principle:

Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Reduces power usage for satellite SSB transmission and UE initial cell search time, conserving power and simplifying hardware requirements.

Implementation Method 1

monitoring a frequency to detect a synchronization signal block (SSB), wherein the frequency is monitored during a search window

Methodology Applied

Scientific EffectSignal detection:

Data Source

PatentUS20250351097A1Global navigation satellite system assisted synchronization signal block transmission in nonterrestrial networks

Publication Date: 2025.11.13 QUALCOMM INC

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive information indicating a reference time. The UE may monitor a frequency to detect a synchronization signal block (SSB), wherein the frequency is monitored during a search window, wherein a start of the search window is determined based at least in part on the reference time, and wherein a duration of the search window is less than a periodicity at which the SSB is transmitted. Numerous other aspects are described.