Low Power Signal Generation via IFFT Spectrum Distribution

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional low power signals suffer from poor transmission performance due to channel frequency selective fading, leading to signal waveform distortion and impaired demodulation.

Innovation Solution

Performing inverse fast Fourier transform (IFFT) processing on a first sequence, which is determined based on to-be-transmitted information, and applying operations such as multiplication with a phase adjustment sequence, cyclic shifting, or repeated superposition to distribute spectrum energy at different frequencies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If conventional OOK modulation is used for low power signal, then power consumption is reduced, but transmission performance deteriorates due to frequency selective fading and signal distortion

Engineering Contradiction:
Improvepower consumptionVSAvoidtransmission performance
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent changes the modulation parameters from conventional OOK to a transformed signal format using IFFT processing. The base sequence undergoes mathematical transformation (IFFT) to create a new signal representation that distributes energy across multiple frequencies, fundamentally changing the signal's frequency domain characteristics to resist fading effects while maintaining low power operation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies preliminary processing operations (phase adjustment, cyclic shifting, repeated superposition) to the base sequence before IFFT transformation. These pre-processing steps modify the sequence characteristics in advance, ensuring that the final transformed signal has optimal properties for resisting frequency selective fading and improving demodulation performance

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If spectrum energy is concentrated at central location using conventional OOK, then modulation is simple, but signal is prone to frequency selective fading and waveform distortion

Engineering Contradiction:
Improvemodulation complexityVSAvoidfrequency selective fading
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the concentrated spectrum energy into multiple frequency components through IFFT processing. Instead of having all energy at one central frequency, the transformed signal distributes energy across many frequency sub-components, so that fading at any single frequency does not destroy the entire signal

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a time-domain concentrated signal to a frequency-domain distributed signal by applying IFFT. This dimensional transformation in the frequency domain creates a signal structure that is inherently more robust to frequency selective effects, as the information is encoded across multiple frequency dimensions rather than a single frequency

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP4668686A1Method and apparatus for generating low power consumption signal, terminal, and network-side device
Publication Date: 2025.12.24 VIVO MOBILE COMM CO LTD
  • EP4668686A1 patent drawingFigure 1~3A
  • EP4668686A1 patent drawingFigure 3B~3D
  • EP4668686A1 patent drawingFigure 4A~4C

AI summary

The present application discloses a method and apparatus for generating a low power consumption signal, a terminal and a network-side device, and belongs to the technical field of communication. The method for generating a low power consumption signal, of the embodiment of the present application, comprises: a communication device executing a target operation on a first sequence to obtain a first signal; the communication device performing inverse fast Fourier transform (IFFT) processing on the first signal to obtain a low power consumption signal; wherein the first sequence is determined on the basis of information to be transmitted, and the target operation comprises any one of the following: multiplying the first sequence by a phase adjustment sequence to obtain a second signal, then multiplying the second signal by a first preprocessing matrix; multiplying the first sequence by a first preprocessing matrix to obtain a second sequence, then performing target processing on the second sequence, the target processing being used for performing repeated overlapping on the second sequence following a cyclic shift, or for performing phase adjustment on the second sequence.