Interference Power Estimation for Satellite Ground Links
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Solution Overview
Problem
Current interference coordination technologies are inadequate for calculating incoming interference power from a satellite in abnormal states, as they rely on ground surface power flux density limits, which may be exceeded when satellites emit radio waves at high gain and high transmission power, potentially causing interference beyond acceptable levels.
Innovation Solution
An interference power estimation method that calculates an inter-station vector, determines antenna direction vectors, and computes antenna directivity and propagation losses for multiple satellite positions, allowing for accurate estimation of interference power by considering both horizontal and vertical antenna directivity and minimizing attenuation sums.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ground surface power flux density limits are used for interference coordination, then normal satellite operations can be coordinated, but interference power cannot be accurately calculated when satellites are in abnormal states
Solution Approach 1:
The patent changes the calculation parameters from ground surface power flux density limits to satellite transmission parameters including transmission power, antenna gain, and directivity patterns. This allows accurate interference power calculation by using actual satellite transmission characteristics rather than generic ground limits, resolving the contradiction between reliability and measurement precision.
Solution Approach 2:
The patent introduces dynamic calculation that adapts to different satellite states (normal and abnormal). By dynamically adjusting the calculation model based on satellite transmission parameters and antenna directivity, the system maintains accuracy across varying operational conditions, addressing the limitation of static ground surface power flux density limits.
2Power
If satellites emit radio waves at high gain and high transmission power, then communication capability is improved, but interference power to ground stations increases beyond acceptable levels
Solution Approach 1:
The patent applies local quality by considering the directional characteristics of antenna radiation patterns. Instead of treating interference uniformly in all directions, the calculation incorporates antenna directivity to assess interference power specifically in the direction of ground stations, allowing high transmission power to be used while controlling directional interference to acceptable levels.
Solution Approach 2:
The patent implements a feedback mechanism where calculated interference power is compared against allowable interference power at ground stations. This feedback loop enables operators to adjust transmission parameters to maintain communication capability while ensuring interference remains within acceptable limits, resolving the contradiction between high power transmission and interference control.
Data Source
AI summary
The interference power estimation apparatus 1 calculates an inter-station vector from an interfering station over a sphere to an interfered station installed in the sphere based on a position of each station. In a case where a line segment connecting the position of the interfered station and the position of the interfering station does not intersect with the sphere, an angle between an antenna direction vector representing a direction of an antenna from the position of the interfered station and the inter-station vector is derived, and a sum of an antenna directivity attenuation amount obtained based on the angle and propagation losses calculated based on a distance between the interfered station and the interfering station is calculated. The interference power estimation apparatus 1 calculates the sum for each of a plurality of possible positions of the interfering station, but does not calculate the sum in a case where the line segment connecting the position of the interfered station and the position of the interfering station intersects with the sphere. The interference power estimation apparatus 1 calculates interference power from the interfering station, based on a minimum value of the calculated sum.