Shape-Shifted Sinusoidal Waveforms for Spectral Efficiency
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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
A method for periodic waveform modulation that encodes input digital data at selected phase angles of a sinusoidal waveform, creating modulated sinusoidal waveforms with data notches that balance energy across phase angles, allowing for efficient data transmission with reduced power usage and increased spectral efficiency.
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 spectral efficiency is reduced
Solution Approach 1:
The patent changes the fundamental parameter of waveform shape from conventional sinusoidal modulations to shape-shifted waveforms with variable amplitude profiles. By modifying the waveform shape parameter rather than just amplitude, frequency, or phase, the system achieves higher spectral efficiency (up to 20 bits/second/Hz) and better power efficiency simultaneously, resolving the contradiction between data throughput and power efficiency
Solution Approach 2:
The patent employs periodic pulse-amplitude modulation where the waveform consists of periodic pulses with amplitudes representing data bits. This periodic structure allows for efficient synchronization and detection while maintaining high spectral efficiency. The periodic nature enables the system to achieve high data throughput through repeated transmission cycles with optimized energy distribution
2Productivity
If higher order QAM modulation is used to increase data rates, then data throughput is improved, but peak to average power ratio increases causing signal degradation
Solution Approach 1:
The patent changes from conventional QAM's amplitude and phase modulation to shape-shifted waveforms where the entire waveform shape is modulated. This parameter change allows achieving high data rates (20 bits/second/Hz) while maintaining constant envelope characteristics, thus avoiding the peak-to-average power ratio problems that cause signal degradation in high-order QAM systems
3Device complexity
If conventional sinusoidal modulation is used, then implementation is simple, but spectral efficiency is low limiting data capacity
Solution Approach 1:
The patent uses periodic pulse-trains as the basis for modulation, which maintains implementation simplicity through regular, repeating patterns. The periodic structure allows for easy generation and synchronization while achieving high spectral efficiency (up to 20 bits/second/Hz) through optimized pulse amplitude assignment and shaping, thus resolving the contradiction between simplicity and spectral efficiency
Data Source
AI summary
A data communication method in which input digital data is received and encoded into an encoded waveform having zero crossings representative of the input digital data. The encoding includes generating the encoded waveform based upon a continuous piecewise function having sinusoidal components. The continuous piecewise function may be used in generating a plurality of symbol waveforms, each of which occupies a period of the encoded waveform and represents bits of the input digital data. The plurality of symbol waveforms are defined so that a value of a phase offset used in the continuous piecewise function is different for each of the plurality of symbol waveforms, thereby resulting in each symbol waveform having a different zero crossing. An encoded analog waveform is generated from a representation of the encoded waveform and transmitted to a receiver.