Direct Amplitude Coded Carrier Wave Transmitter for Spectral Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing wireless communication technologies face challenges in efficiently utilizing the limited RF spectrum for high data rate transmissions without interfering with other transmissions, as the demand for wireless data transmission exceeds the available spectrum.
Innovation Solution
A frequency agile radio system that directly codes data onto a carrier wave using a transmitter with an oscillator, mapping unit, digital to analog converter, and filter to generate a modulated carrier wave, and a receiver that processes composite signals to isolate and decode the directly coded carrier wave, allowing for efficient data transmission and reception without interfering with other signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional up-conversion mixing is used to transmit data, then data transmission capability is achieved, but spectral occupancy increases and interference with other transmissions occurs
Solution Approach 1:
The patent changes the fundamental parameter of how data is encoded onto the carrier wave. Instead of using traditional frequency or phase modulation that creates wide spectral occupancy, the invention uses direct amplitude coding of the carrier wave itself, where data bits directly control the amplitude levels of the carrier. This parameter change enables high data transmission rates while minimizing spectral occupancy to only the essential carrier frequency bandwidth.
2Productivity
If more spectrum is allocated for wireless transmission, then higher data rates can be achieved, but spectrum is a finite resource and cannot be expanded
Solution Approach 1:
The patent implements a dynamic spectrum access system where the transmitter continuously monitors the RF environment to detect occupied frequency bands and dynamically selects available frequencies for transmission. This dynamic approach allows the system to adaptively utilize the finite spectrum resource, achieving high data transmission rates by continuously finding and exploiting unused spectral opportunities without requiring additional spectrum allocation.
3Area of stationary object
If carrier wave amplitude is directly coded with data, then spectral efficiency is improved, but the system complexity increases compared to traditional modulation
Solution Approach 1:
The patent replaces traditional analog modulation mechanisms (mixers, modulators, filters) with digital signal processing techniques. Data bits are directly converted to amplitude control signals that modulate the carrier wave digitally. This substitution of mechanical/analog systems with digital processing simplifies the overall system architecture while achieving direct amplitude coding, thereby improving spectral efficiency without proportionally increasing system complexity.
Data Source
AI summary
A transmitter includes an oscillator that generates a clock signal and a mapping unit that maps received data-bits to symbols and designates each of the symbols as three or more signal coding levels, where each of the signal coding levels are represented by a plurality of digital codes. The three or more signal coding levels representing each symbol are DC balanced and include a plurality of peak amplitudes. The transmitter further includes a digital to analog convertor that converts the plurality of digital codes to a corresponding plurality of analog amplitude levels at a rate determined by the clock signal, whereby the analog amplitude levels generate a signal coding level. A filter then smoothes the plurality of analog amplitude levels and generates a modulated carrier wave that is coded by the symbols.