Narrowband Synchronization Signals for LTE Coexistence
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Solution Overview
Problem
The existing wireless communication systems face challenges in enhancing the cell search performance of user equipment (UE) in narrowband Internet of Things (NB-IoT) systems, particularly due to limitations in synchronization signal design, which affects interference with neighboring LTE terminals and requires a new frame structure in the time domain to reduce costs.
Innovation Solution
The introduction of new narrowband primary synchronization signals (NPSS) and narrowband secondary synchronization signals (NSSS) configured in similar structures to legacy signals, allowing for improved cell search performance by acquiring necessary information and optimizing signal transmission in NB-IoT systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a new frame structure is designed in the time domain to reduce bandwidth and cost, then communication cost is reduced, but interference with existing neighboring LTE terminals occurs and system complexity increases
Solution Approach 1:
The patent segments the synchronization signal transmission into specific time resources (subframes 1 and 6) within the frame structure, separating NB-IoT synchronization signals from LTE data transmissions. This temporal segmentation allows NB-IoT to operate in bandwidth-reduced mode while preventing interference to LTE terminals by confining NB-IoT signals to designated time slots.
Solution Approach 2:
The patent implements dynamic resource allocation where the frame structure adapts to accommodate both LTE and NB-IoT requirements. The system dynamically assigns specific subframes for NB-IoT synchronization signals while preserving LTE functionality in other resources, enabling the system to transition between different operational modes based on traffic requirements and interference conditions.
2Measurement precision
If synchronization signal design is modified for NB-IoT, then cell search performance is improved, but compatibility with legacy systems may be affected
Solution Approach 1:
The patent applies local quality by making synchronization signals NB-IoT-specific in terms of frequency positioning and time resource allocation, while maintaining overall frame structure compatibility with LTE. The synchronization signals are designed with NB-IoT optimized parameters (narrower bandwidth, specific subframe locations) that improve cell search performance for NB-IoT devices without disrupting LTE operations in other frequency and time resources.
Solution Approach 2:
The patent uses the frame structure itself as an intermediary mechanism that mediates between NB-IoT synchronization requirements and LTE compatibility. By embedding NB-IoT synchronization signals within the existing LTE frame structure at specifically designated resources, the frame structure acts as a mediator that enables both NB-IoT cell search optimization and LTE system compatibility to coexist.
Data Source
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AI summary
The present invention provides a method for a terminal operating by means of utilizing a defined synchronization signal in a wireless communication system supporting narrow band-Internet of Things (NB-IoT), and a device for supporting same.