Transpositional Modulation Waveform Generation and Demodulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing transmission systems face limitations due to bandwidth constraints and amplitude variation errors in generating and demodulating transpositional modulation signals, which are not effectively addressed by existing carrier modulation methods.
Innovation Solution
The method involves generating quarter-cycle waveforms based on input signals, assembling them into continuous output signals with specific inflections to represent input levels, and using third harmonic sidebands for frequency-shifting and demodulation, including phase detection and fast Fourier transform analysis to overcome amplitude variation and bandwidth limitations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If existing carrier modulation methods are used to maximize energy throughout the assigned channel bandwidth, then information bandwidth is maximized, but amplitude variation errors are introduced that require removal by adjusting circuits
Solution Approach 1:
The patent changes the fundamental parameter of carrier modulation by introducing Transpositional Modulation (TM) which operates independently from traditional AM/FM/PM. The TM modulation creates inflections in the carrier waveform that encode information without affecting amplitude, frequency, or phase, thereby eliminating amplitude variation errors while maintaining maximum information bandwidth utilization
Solution Approach 2:
The patent segments the carrier waveform into distinct quarter-cycle segments with specific inflection points. By dividing the carrier cycle into segments and controlling inflections at specific points (first inflection between negative peak and positive peak, second inflection between positive peak and negative peak), the system achieves precise control over information encoding without introducing amplitude errors
2Adaptability or versatility
If Transpositional Modulation is applied to add information to a carrier signal without affecting amplitude, frequency or phase, then existing de-modulators cannot detect the modulation, but this creates a need for specialized demodulation systems
Solution Approach 1:
The patent introduces third harmonic sidebands as an intermediary mechanism that bridges the gap between the invisible TM modulation and detectable signals. By generating third harmonic sidebands from the TM modulated carrier, the system creates detectable frequency components that can be used for demodulation while maintaining the original carrier's amplitude, frequency, and phase integrity
Solution Approach 2:
The patent moves the information detection from the time domain (where TM inflections are invisible) to the frequency domain through third harmonic generation. By transforming the problem into a different dimension (frequency analysis), the system enables detection of TM modulation using standard frequency-based demodulation techniques, reducing the need for complex specialized circuits
3Measurement precision
If quarter-cycle waveforms are assembled into continuous output signals with inflections to represent input levels, then transpositional modulation is achieved, but amplitude variation errors may still exist between negative peaks
Solution Approach 1:
The patent implements feedback mechanisms in the waveform generation process by continuously monitoring and adjusting the quarter-cycle assembly to ensure consistent amplitude characteristics. The system uses the generated third harmonic sidebands as feedback to verify and correct amplitude variations, ensuring that negative peaks maintain consistent amplitude levels while preserving the inflection-based information encoding
Data Source
AI summary
Systems and methods for transpositional modulation and demodulation are provided. One such method for generating a signal includes the steps of providing a look-up table having a plurality of quarter-cycle waveforms, each of said quarter-cycle waveforms associated with a respective input level; receiving an input signal; and outputting quarter-cycle waveforms associated with levels of the received input signal. Systems for transpositional modulation are also provided. One such system for generating a signal includes a look-up table having a plurality of quarter-cycle waveforms. Each of the quarter-cycle waveforms are associated with a respective input level, and the look-up table is configured to receive an input signal, and output quarter-cycle waveforms associated with levels of the received input signal.