Satellite User Equipment Frequency Search Using Detection Windows
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Solution Overview
Problem
In satellite communication systems, the frequency offset due to satellite movement and distance causes delays in identifying the target frequency for signal reception, necessitating a method to improve the search speed for the frequency at which the received signal is present.
Innovation Solution
User equipment generates a detection window with a wide search range by correlating a search signal with a received signal, selecting a first detection window with the largest correlation value, and identifying the target frequency within this window to reduce the number of searches required.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the user equipment searches for the target frequency by checking each preset reference frequency individually, then the search can be performed systematically, but the search time becomes excessively long due to frequency offset
Solution Approach 1:
The patent divides the frequency search process into two stages: first, generate detection windows for multiple preset reference frequencies simultaneously to identify a candidate frequency band; second, perform precise frequency identification within the selected band. This segmentation reduces the overall search time while maintaining accuracy.
Solution Approach 2:
The patent performs preliminary action by generating detection windows for all preset reference frequencies in advance and identifying a candidate frequency band before conducting the final precise frequency search. This preliminary filtering step significantly reduces the time required for the subsequent detailed search.
2Area of stationary object
If the user equipment increases the number of frequency points to search, then the frequency search coverage is improved, but the number of searches increases and search speed decreases
Solution Approach 1:
The patent segments the wide frequency search space into multiple detection windows corresponding to preset reference frequencies. By processing multiple frequency points in parallel through window generation and selecting the window with the maximum correlation value, the system achieves wide coverage without proportionally increasing the number of sequential searches.
Solution Approach 2:
The patent merges the search for multiple frequency points into a unified detection window generation process. Instead of searching each frequency point separately, the system combines them into detection windows that can be processed together, thereby improving search efficiency while maintaining comprehensive frequency coverage.
3Speed
If the user equipment uses a narrow detection window for frequency search, then the correlation calculation is faster, but the frequency offset cannot be properly detected
Solution Approach 1:
The patent segments the frequency search into a two-stage process: first using wider detection windows to identify the candidate frequency band with proper frequency offset detection, then performing narrower searches within the selected band for precise frequency identification. This segmentation allows each stage to optimize for its specific purpose.
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
This approach significantly reduces the time needed to find the target frequency by searching a wider frequency band with a smaller number of searches, enhancing the efficiency of satellite communication access.
Implementation Method 1
generating, for each of a plurality of reference frequencies, a plurality of correlation values based on a search signal corresponding to the shared signal and the received signal
Data Source
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AI summary
Provided is an operation method of user equipment, the operation method including receiving a received signal including a frequency offset and a shared signal transmitted from a satellite, generating a plurality of correlation values, by correlating a search signal corresponding to the shared signal with the received signal, for each of a plurality of predefined reference frequencies, selecting a first detection window comprising a largest correlation value, among a plurality of detection windows including the plurality of correlation values corresponding to each of the plurality of reference frequencies, and identifying a target frequency for communicating with the satellite by searching a frequency band corresponding to a search width of the first detection window.