Adaptive Modulation Control for Interference-Limited Communications
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Solution Overview
Problem
Existing communications systems face inefficiencies due to environmental factors that cause interference and errors in signal transmission, limiting the spectral efficiency of modulation and coding schemes, and leading to frame losses and reduced data throughput.
Innovation Solution
A system that dynamically selects the most spectrally efficient modulation and coding scheme by monitoring carrier and environmental parameters, using a combination of analytical methods and machine learning to adapt to changing conditions, ensuring reliable data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high-order modulation schemes are used to increase spectral efficiency, then data throughput is improved, but reliability deteriorates due to environmental interference and signal degradation
Solution Approach 1:
The system dynamically adapts the modulation and coding scheme based on real-time channel conditions. The modem continuously monitors signal quality metrics and adjusts the modcod scheme accordingly, transitioning between different modulation orders (e.g., QPSK, 16-QAM, 64-QAM) and coding rates to optimize the trade-off between spectral efficiency and reliability under varying environmental conditions.
Solution Approach 2:
The system changes key parameters of the communication scheme including modulation order, coding rate, and frame structure based on channel quality. By adjusting these parameters dynamically, the system can operate at higher spectral efficiency when conditions permit while maintaining reliability through lower-order modulation and stronger error correction when environmental interference increases.
2Reliability
If forward error correction is increased to improve reliability, then frame error rate is reduced, but spectral efficiency deteriorates due to increased redundancy overhead
Solution Approach 1:
The error correction capability is dynamically adjusted based on channel conditions. The system uses adaptive coding rate selection where the proportion of redundancy bits varies with signal quality. During good channel conditions, the system reduces redundancy overhead to maximize spectral efficiency, while during poor conditions, it increases forward error correction capability to maintain acceptable frame error rates.
Solution Approach 2:
The system changes the coding rate parameter of the forward error correction scheme based on measured channel quality. By selecting from multiple available coding rates (e.g., 1/2, 2/3, 3/4, 5/6), the system optimizes the balance between reliability and spectral efficiency, using stronger correction only when environmental factors degrade the channel.
3Ease of operation
If fixed modulation schemes are used to simplify system operation, then device complexity is reduced, but adaptability deteriorates in changing environmental conditions
Solution Approach 1:
The system implements automatic modulation and coding scheme selection that adapts to changing environmental conditions without requiring manual intervention. The modem continuously monitors channel quality indicators and automatically selects the appropriate modcod scheme from a predefined set of supported configurations, maintaining ease of operation while achieving high adaptability to varying propagation conditions.
Solution Approach 2:
The communication system performs self-adjustment by automatically selecting optimal modulation and coding parameters based on real-time channel measurements. The system monitors its own performance metrics and environmental conditions, then autonomously configures the appropriate transmission scheme without external control, combining operational simplicity with environmental adaptability.
Data Source
AI summary
Communications devices, communications systems and associated communications methods are described. According to one aspect, a communications device includes processing circuitry configured to access a value indicative of a signal to noise ratio of a communications signal received at a second communications device of a communications system after transmission of the communications signal from a first communications device of the communications system at a first moment in time, select one of a plurality of different adjustments, and use the value and the one adjustment to control a communications parameter of the communications signal transmitted at a second moment in time after the first moment in time.