Wireless Synchronization Using ISI-Free Interval Detection

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Solution Overview

Problem

Current cellular network synchronization methods are complex and require significant hardware for frame synchronization, with limitations in simplification and efficiency, particularly in recognizing cell location and handling inter-symbol interference.

Innovation Solution

A wireless communication system synchronization method that involves detecting an inter-symbol interference-free interval, setting a fast Fourier transform window endpoint, calculating frequency offsets, finding a preamble sequence, and determining the frame start point using arithmetic units in user equipment to simplify and enhance synchronization processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional frame synchronization methods are used, then cell location recognition can be achieved, but hardware complexity increases and synchronization efficiency decreases

Engineering Contradiction:
Improvesynchronization accuracyVSAvoidhardware requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and removes the complex normalization operation hardware from the frame synchronization process. By identifying that normalization is not essential for achieving synchronization accuracy, the design eliminates this hardware component, thereby reducing device complexity while maintaining synchronization reliability through alternative methods such as direct correlation detection and peak identification algorithms.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces complex, expensive hardware normalization circuits with simpler, software-based processing approaches. By using computationally efficient algorithms that can be implemented in standard processors rather than dedicated hardware, the system achieves the same synchronization functionality with lower hardware requirements and reduced cost.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Measurement precision

If normalization operations are performed in frame synchronization, then synchronization accuracy can be maintained, but hardware complexity and processing overhead increase

Engineering Contradiction:
Improvesynchronization precisionVSAvoidnormalization hardware
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent removes the normalization operation from the frame synchronization process by demonstrating that it is not a necessary step for achieving accurate synchronization. The system achieves comparable or superior precision through direct signal correlation and peak detection methods, eliminating the need for separate normalization hardware and reducing overall system complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the processing approach by altering the mathematical operations performed during synchronization. Instead of performing normalization followed by correlation, the system uses modified correlation algorithms that inherently account for signal energy variations, thereby achieving the same precision effect without the explicit normalization step and associated hardware complexity.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If complex synchronization algorithms are used, then synchronization accuracy improves, but processing time and computational load increase

Engineering Contradiction:
Improveframe synchronization accuracyVSAvoidsynchronization time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the synchronization process into distinct, optimized stages: signal reception, correlation computation, peak detection, and frame start identification. By dividing the overall process into manageable segments with specialized algorithms for each stage, the system achieves high synchronization accuracy while minimizing total processing time through efficient resource allocation and parallel processing where applicable.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by performing correlation detection only on relevant signal portions and using early termination strategies when sufficient synchronization information is obtained. Instead of processing the entire signal duration with full computational complexity, the system identifies and processes only the critical segments needed for accurate frame synchronization, thereby reducing overall processing time while maintaining reliability.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS11825434B2Method and architecture of synchronization of wireless communication system
Publication Date: 2023.11.21 NAT YANG MING CHIAO TUNG UNIV
  • US11825434B2 patent drawing
  • US11825434B2 patent drawing
  • US11825434B2 patent drawing

AI summary

A method of synchronization of wireless communication system is provided. The method includes the following steps: receiving a symbol from a wireless communication system by a user equipment; detecting ISI-free region of the received symbol; setting an endpoint of a FFT window within the ISI-free region; detecting shifted primary control frequency and shifted secondary control frequency of the symbol; calculating ICFO based on the shifted primary control frequency and a primary control frequency; calculating secondary control frequency based on ICFO and shifted secondary control frequency; finding the preamble of a frame based on the secondary control frequency; and determining, based on the preamble, a start point of the frame.