Spread-Spectrum Video Transport With QAM for Signal Resilience
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Solution Overview
Problem
Electromagnetic pathways degrade electromagnetic signals due to attenuation, reflections, and impinging aggressor signals, leading to imperfect signal transmission quality.
Innovation Solution
Combining quadrature amplitude modulation (QAM) with spread-spectrum video transport (SSVT) to modulate and demodulate encoded analog or digital samples, distributing MSBs and LSBs to I and Q components for improved signal resilience and error tolerance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electromagnetic signal transmission is used, then the transmission is simple, but the signal quality degrades due to attenuation, reflections, and impinging aggressor signals
Solution Approach 1:
The patent combines spread-spectrum modulation and quadrature amplitude modulation into a single transmission system. The spread-spectrum encoded signal is modulated onto a carrier wave using QAM, merging two modulation techniques to achieve both error correction and efficient bandwidth utilization, thereby improving signal quality without excessive complexity
Solution Approach 2:
The patent changes the modulation parameters by using quadrature amplitude modulation with varying amplitude and phase to represent encoded signal levels. This parameter transformation allows the signal to be more resilient to degradation from attenuation and interference, improving reliability while maintaining manageable system complexity
2Reliability
If spread-spectrum encoding is used, then error correction is improved, but the bandwidth consumption increases
Solution Approach 1:
The patent transitions from time-domain spread-spectrum encoding to a combination of time-domain encoding and frequency-domain QAM modulation. By adding the frequency dimension through carrier wave modulation, the system achieves error correction benefits while confining the signal to a narrower effective bandwidth, thus resolving the bandwidth consumption issue
3Quantity of substance
If quadrature amplitude modulation is used, then information density is increased, but the system complexity increases
Solution Approach 1:
The patent segments the information transmission into two independent parts: spread-spectrum encoding for error correction and QAM modulation for efficient packing. By segmenting these functions, the system achieves high information density through QAM while the spread-spectrum layer handles reliability, making the overall complexity manageable through functional separation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enhances signal quality by increasing information density and resilience to noise, especially in imperfect electromagnetic pathways, ensuring accurate transmission of high-resolution video signals.
Implementation Method 1
combining quadrature amplitude modulation (QAM) with the transport of encoded signals
Implementation Method 2
encoded signals using a spread-spectrum video transport (SSVT) technique
Data Source
AI summary
A quadrature amplitude modulation (QAM) transmitter separates an input digital level into I and Q components. In a variation, a QAM transmitter uses every other input digital level as an I or Q component. A QAM receiver receives a QAM modulated signal and outputs digital levels. A QAM transmitter for transmitting analog levels uses a pair of input analog levels as the I and Q components. A QAM receiver receives a QAM modulated signal and outputs analog levels. The digital and analog input levels are produced by encoding N samples using L orthogonal codes.