Sinusoidal Notch Encoding for High-Spectral-Efficiency Data Links
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Solution Overview
Problem
Current data communication systems face challenges in increasing data throughput and addressing signal degradation, particularly due to transmission path delay, interference, and non-linearity, with existing modulation techniques like Amplitude Modulation, Frequency Modulation, QAM, QPSK, PSK, and APSK having inefficiencies in power usage, bandwidth, and error rates.
Innovation Solution
The method involves periodic waveform modulation by encoding input digital data at selected phase angles of a sinusoidal waveform to create a modulated sinusoidal waveform with data notches, balancing energy across phase angles to minimize sidebands and harmonics, allowing for high spectral efficiency and efficient data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional modulation techniques (AM, FM, QAM, QPSK, PSK, APSK) are used to increase data throughput, then data transmission capacity is improved, but power efficiency deteriorates and bandwidth usage becomes inefficient
Solution Approach 1:
The patent changes the fundamental parameter of waveform selection from conventional modulated carriers to unmodulated sinusoidal waveforms. By encoding data directly into the sinusoidal waveform through selective amplitude modulation at specific phase angles (creating data notches), the system achieves high data throughput while maintaining constant envelope and excellent power efficiency, avoiding the power inefficiency of traditional modulation schemes
Solution Approach 2:
The patent replaces the mechanical modulation process (varying amplitude, frequency, or phase of carriers) with a digital encoding process that creates data notches in unmodulated sinusoidal waveforms. This substitution eliminates the need for complex modulation/demodulation hardware while achieving comparable or superior data transmission rates with better power efficiency
2Productivity
If QAM modulation is used to achieve high data rates, then data throughput is improved, but peak to average power ratio increases
Solution Approach 1:
The patent changes from QAM's varying amplitude and phase parameters to constant envelope sinusoidal waveforms with data encoded as notches at specific phase angles. This parameter change maintains constant amplitude (eliminating peak power issues) while achieving high data rates through multiple notches per waveform period, directly resolving the high peak-to-average power ratio problem of QAM
3Productivity
If higher order QAM modulation is used to increase data rates, then more power levels are required, but device complexity increases
Solution Approach 1:
The patent replaces QAM's multiple power levels with a single constant power level, encoding data instead through the presence or absence of notches at specific phase angles. This simplifies the transmitter to require only one power amplifier operating at constant power, eliminating the complexity of multiple power levels and associated switching mechanisms required in higher order QAM systems
4Productivity
If conventional modulation techniques are used to transmit data, then data communication is achieved, but spectral efficiency is poor
Solution Approach 1:
The patent uses periodic unmodulated sinusoidal waveforms as the carrier, with data encoded as periodic notches at specific phase angles within each waveform period. This periodic structure allows for extremely compact spectral occupancy while maintaining high data rates, achieving superior spectral efficiency compared to conventional modulation techniques that require broader bandwidths
Solution Approach 2:
The patent changes from modulated carriers occupying broad spectral bands to unmodulated sinusoidal waveforms with notch-encoded data that occupy minimal spectrum. The constant frequency and phase of the unmodulated carrier, combined with narrow notches, concentrate energy efficiently in the frequency domain, achieving high spectral efficiency
Data Source
AI summary
A method of recovering information encoded by a modulated sinusoidal waveform having first, second, third and fourth data notches at respective phase angles, where a power of the modulated sinusoidal waveform is reduced relative to a power of an unmodulated sinusoidal waveform within selected ones of the first, second, third and fourth data notches so as to encode input digital data. The method includes receiving the modulated sinusoidal waveform and generating digital values representing the modulated sinusoidal waveform. A digital representation of the unmodulated sinusoidal waveform is subtracted from the digital values in order to generate a received digital data sequence, which includes digital data notch values representative of the amplitude of the modulated sinusoidal waveform within the first, second, third and fourth data notches. The input digital data is then estimated based upon the digital data notch values.