Signal Analyzer Frame Segmentation for Resolution Trade-off
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Solution Overview
Problem
Existing signal analyzers face a trade-off between time and frequency resolution, where increasing the time length of a frame to achieve higher frequency resolution results in lower time resolution, making it difficult to observe signals from various aspects at different resolutions.
Innovation Solution
The apparatus and method allow for the production and display of frequency domain data at different time and frequency resolutions by selecting specific frames on a spectrogram, where the time domain data of these frames is reprocessed to generate new frequency domain data with adjustable frame sizes, enabling separate display of spectra with varying resolutions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the time length of a frame is increased to achieve higher frequency resolution, then frequency resolution is improved, but time resolution deteriorates
Solution Approach 1:
The patent segments the time domain data into multiple overlapping frames with different time lengths. Short frames provide high time resolution while long frames provide high frequency resolution. The segmentation allows the system to simultaneously maintain both types of frames and display them as separate spectrograms, resolving the contradiction between frequency and time resolution.
Solution Approach 2:
The patent adds a temporal dimension to the frequency domain analysis by creating a library of frequency domain data corresponding to different time frames. Instead of a single frequency spectrum, the system generates multiple spectra at different time points, transforming the analysis from a 2D frequency-power representation to a 3D time-frequency-power representation, thereby simultaneously providing both high time and frequency resolution.
2Measurement precision
If the frame size is increased to improve frequency resolution, then frequency resolution is improved, but the amount of processing data increases
Solution Approach 1:
The patent divides the total time domain data into multiple smaller frames that can be processed independently and in parallel. By segmenting the data, the system reduces the computational burden on each individual processing task while maintaining high frequency resolution through the use of sufficiently long frame durations within each segment.
Solution Approach 2:
The patent performs preliminary processing by creating an overlap between adjacent frames and pre-calculating the frequency domain data for each frame before final assembly. This preliminary action allows the system to prepare data in smaller, more manageable units that can be processed efficiently while maintaining the overall high frequency resolution required.
Data Source
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AI summary
A signal analyzer provides frequency domain data at different time and frequency resolution. First type frequency domain data is derived from time domain data of a signal under test by first type frames and displayed as a spectrogram. A selecting box is displayed on the spectrogram for selecting the first type frames. The signal analyzer produces second type frequency domain data by treating the time domain data corresponding to the first type frequency domain data included in the selected first type frames with the selecting box as one frame by FFT calculation. The resultant second type frequency domain data are displayed as a spectrum that has different time and frequency resolution from the spectrogram.