G-H-S Laser Comms via HAP Relay and Non-Kolmogorov Turbulence Model
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Solution Overview
Problem
Current satellite-ground laser communication systems face interference and reduced performance due to atmospheric turbulence and cloud obstruction, with existing isotropic Kolmogorov turbulence models inadequately describing the effects on optical wave transmission in the stratosphere, particularly in ground-satellite uplink communications.
Innovation Solution
A G-H-S laser communication system employing an anisotropic non-Kolmogorov turbulence model and hexagon quadrature amplitude modulation (HQAM) to analyze and mitigate atmospheric turbulence effects, using a high-altitude platform (HAP) in the stratosphere as a relay station to enhance transmission quality and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If an isotropic Kolmogorov turbulence model is adopted for HAP in satellite laser communication, then the model is simple and widely used, but it cannot accurately analyze the influence of eddy currents on optical wave transmission in the stratosphere
Solution Approach 1:
The patent changes the turbulence model parameters from isotropic Kolmogorov to anisotropic non-Kolmogorov, adjusting the power law index and structure constant to match stratospheric conditions. This parameter change enables accurate modeling of eddy current effects while maintaining computational feasibility.
Solution Approach 2:
The patent applies different turbulence characteristics to different regions of the stratosphere, recognizing that eddy current effects vary with altitude and spatial location. The anisotropic model captures these local variations in turbulence intensity and directionality.
2Ease of manufacture
If traditional modulation techniques (DPSK, MSK, QAM) are used in satellite-ground laser communication, then the system is simple and compatible with existing standards, but energy efficiency and spectrum utilization are suboptimal
Solution Approach 1:
The patent changes the modulation parameters by introducing hexagon-shaped signal constellations instead of traditional circular or square QAM patterns. This geometric parameter change optimizes the signal distribution to match the turbulence-induced intensity fluctuations, improving energy efficiency and reducing bit error rates.
Solution Approach 2:
The patent employs asymmetric hexagonal modulation patterns that differ from the symmetric circular QAM constellations. This asymmetry allows the modulation scheme to better accommodate the anisotropic turbulence effects, improving spectral efficiency and power utilization.
3Productivity
If a laser beam is transmitted through the atmosphere, then the communication can be established, but the beam is obstructed by clouds and affected by atmospheric turbulence, causing jitter, divergence, and transmission quality degradation
Solution Approach 1:
The patent introduces a HAP (high-altitude platform) as an intermediary relay station between the ground and satellite. This intermediary positioned in the stratosphere acts as a relay that receives laser beams from the ground, processes them, and retransmits to the satellite, bypassing the most severe turbulence and cloud obstruction zones.
Solution Approach 2:
The patent segments the communication path into two stages: ground-to-HAP and HAP-to-satellite. This segmentation allows each stage to be optimized independently, with the HAP serving as a relay that mitigates the effects of atmospheric turbulence and cloud obstruction on the overall transmission.
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
The system achieves improved communication performance and stability by accurately modeling stratospheric turbulence and reducing bit error rates, enabling high-speed and long-distance data communication with reduced interference from atmospheric effects.
Implementation Method 1
atmospheric turbulence is also an important factor affecting laser transmission. A refractivity caused by near-surface turbulence is irregularly changed in space and time when the laser beam passes through an atmospheric channel
Implementation Method 2
an anisotropic non-Kolmogorov turbulence model is more suitable for analyzing turbulent effects in the stratosphere
Implementation Method 3
A laser beam is obstructed by clouds during transmission
Implementation Method 4
A refractivity caused by near-surface turbulence is irregularly changed in space and time when the laser beam passes through an atmospheric channel
Implementation Method 5
The multi-aperture receiver is configured to receive the laser signals from branches of the multi-aperture receiver
Implementation Method 6
a hexagon quadrature amplitude modulation (HQAM) is applied in the G-H-S laser communication system
Data Source
AI summary
A ground-high altitude platform-satellite (G-H-S) laser communication system and method based on anisotropic non-Kolmogorov turbulence are provided, and the system includes a ground transmitting terminal, a HAP, a satellite terminal, a ground-HAP uplink and an HAP-satellite uplink. When laser beams are transmitted upwards from the ground transmitting terminal and through the HAP, the laser beams are affected light intensity scintillation, beam drift, and angle of arrival fluctuation, and are transmitted through vacuum channels and received by receiving antenna of the satellite terminal. The HAP is located at stratosphere, and an anisotropic non-Kolmogorov turbulence model is suitable for analyzing turbulence effect in stratosphere. Thus, the anisotropic non-Kolmogorov turbulence model is used to research transmission characteristics of the laser beams. Meanwhile, a hexagon quadrature amplitude modulation (HQAM) is used in the G-H-S laser communication system, which optimizes system performances on basis of improving communication quality, and enhances stability of communication links.