Frequency Division and Superposition for Wireless Signal Utilization

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Solution Overview

Problem

Existing wireless communication systems face inefficiencies in frequency band utilization due to signal component loss when removing sub-spectra during transmission, which affects the signal-to-noise ratio and reception characteristics.

Innovation Solution

The system generates N sub-spectra by dividing the transmission signal and superimposes some sub-spectra in the frequency domain, allowing for frequency conversion and superimposition, thereby increasing frequency utilization efficiency without losing signal components, and uses replica generation and distortion compensation in the receiving device to restore the original signal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If sub-spectra are removed from the transmission signal to improve frequency utilization efficiency, then the occupied bandwidth is reduced, but signal components are lost and reception characteristics deteriorate

Engineering Contradiction:
Improvefrequency utilization efficiencyVSAvoidreception characteristics
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The transmission signal is divided into multiple sub-spectra in the frequency domain. Instead of removing entire sub-spectra, the invention segments them further and selectively removes only specific frequency components within certain sub-spectra, while retaining other components. This segmentation approach allows frequency utilization efficiency to be improved by removing unused frequency components while preserving signal components in retained portions, thereby maintaining reception characteristics.

Inventive Principle:
Principle #1Segmentation

2Quantity of substance

If sub-spectra are removed to reduce occupied bandwidth, then frequency band utilization improves, but signal-to-noise ratio deteriorates due to signal component loss

Engineering Contradiction:
Improveoccupied bandwidthVSAvoidsignal-to-noise ratio
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The invention applies local quality by treating different frequency components within sub-spectra differently. Rather than uniformly removing entire sub-spectra, it selectively removes frequency components only in specific local regions (certain sub-spectra) while preserving components in other regions. This localized approach ensures that signal components are preserved in critical frequency regions, maintaining signal-to-noise ratio while still reducing occupied bandwidth by removing components from non-critical regions.

Inventive Principle:
Principle #3Local quality

3Quantity of substance

If the transmission signal is divided into multiple sub-spectra to improve frequency utilization, then empty bands can be utilized more effectively, but the system complexity increases

Engineering Contradiction:
Improvefrequency band utilizationVSAvoidsystem complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The invention extracts and removes only the specific frequency components corresponding to empty or unused bands from the transmission signal, rather than dividing and transmitting all sub-spectra separately. By extracting and removing only the unnecessary frequency components while retaining the essential signal components, the system achieves improved frequency band utilization without requiring complex multi-sub-spectrum transmission and reception systems, thus avoiding excessive system complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3131250B1Division of a modulated signal into sub-spectra and superposition of sub-spectra in frequency
Publication Date: 2019.07.03 NIPPON TELEGRAPH & TELEPHONE CORP
  • EP3131250B1 patent drawingFigure 1
  • EP3131250B1 patent drawingFigure 2
  • EP3131250B1 patent drawingFigure 3(A)~3(B)

AI summary

The receiving device of the present invention is provided with a means that receives, as a received signal, a signal that has been transmitted a transmitting device by dividing by N the spectrum of a signal to be transmitted and performing spectrum editing to reduce its occupied bands; a means that generates a first decoded signal by error-correcting and decoding this received signal in the bandwidth of the signal to be transmitted; a means that generates a transmission replica signal from this first decoded signal and divides by N the spectrum of this transmission replica signal to generate N sub-replicas; a means that generates a compensated received signal by restoring the spectrum of the signal to be transmitted from the transmitting device using the N sub-replicas and the received signal; and a means that decodes this compensated received signal to generate a second decoded signal.