Adaptive Rate Modem for Free-Space Optical Communication
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Solution Overview
Problem
Communication terminals in free-space optical communication systems face challenges in maintaining reliable operation due to variations in temperature, component wear, and changing optical throughput, which affect pointing accuracy and data rate stability.
Innovation Solution
A communication system that includes sensors and processors to monitor the state of its components, adjust the data rate by selecting from various techniques such as changing the duty cycle, modulation format, baud rate, or bandwidth, based on estimated component states and received power indications, to maintain minimum received power levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional control techniques are used to manage component variations, then the system structure remains simple, but the ability to compensate for variability and maintain reliable operation deteriorates
Solution Approach 1:
The system continuously monitors component state through sensors and adjusts operating parameters based on this feedback. The processor receives sensor data, estimates component state, and modifies transmission parameters accordingly, creating a closed-loop control system that adapts to component variability and maintains reliable operation.
Solution Approach 2:
The system transitions from static control to dynamic adaptation by continuously adjusting transmission parameters based on real-time component state estimation. The data rate and other transmission parameters are dynamically modified according to estimated component degradation, enabling the system to maintain optimal performance despite changing conditions.
2Reliability
If fixed data rate is used, then the system is simple to operate, but the ability to maintain minimum received power during disturbances deteriorates
Solution Approach 1:
The system dynamically adjusts the data rate based on estimated component state and received power conditions. When disturbances are detected or component degradation is estimated, the system automatically modifies transmission parameters to maintain minimum received power, transitioning from fixed to adaptive operation.
Solution Approach 2:
The system uses feedback from power sensors and component state monitoring to automatically adjust data rate. The processor continuously receives power indications, estimates component state, and modifies transmission parameters accordingly, creating a self-regulating system that maintains reliability without manual intervention.
3Adaptability or versatility
If rapid data rate changes are implemented, then the system can quickly adapt to power fluctuations, but the complexity of the modulation and feedback mechanism increases
Solution Approach 1:
The system implements rapid adaptation by changing key transmission parameters such as data rate, modulation format, and coding scheme based on estimated component state. These parameter modifications enable quick response to power fluctuations while maintaining system reliability through structured adaptation mechanisms.
Data Source
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AI summary
The disclosure provides a communication system (102) that includes sensors (118), a plurality of components (112, 114, 116), and processors (104). The sensors (118) receive measurements related to a state of the communication system (102). The processors (104) receive an indication of an amount of received power at a remote communication system (122) and estimate a state of the plurality of components (112, 114, 116) based on the received one or more measurements and the received indication. Using the indication and the estimated state, the processors (104) determine whether the amount of received power is likely to fall below a minimum received power within a given time interval. When it is likely, the processors (104) select an adjustment technique of a plurality of adjustment techniques for adjusting a data rate of the outbound signal and adjust a given component of the communication system (102) using the selected adjustment technique to change the data rate of the outbound signal.