DFT Spectrum Analyzer Video Bandwidth Resolution via Overlapping Frames
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Solution Overview
Problem
Traditional video bandwidth filtering methods are not applicable to Discrete Fourier Transform (DFT) based spectrum analyzers, resulting in coarse resolution and inability to meet specific standards for video bandwidth requirements in applications like WiMax and GSM.
Innovation Solution
A modified trace averaging approach with frame weighting is used to emulate video filtering, allowing for a continuous range of video bandwidths by overlapping resolution bandwidth frames and performing DFT transforms, which increases available video bandwidth resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional trace averaging is used to emulate video filtering in DFT-based spectrum analyzers, then video filtering effect is achieved, but video bandwidth resolution remains coarse
Solution Approach 1:
The spectrum trace is divided into multiple overlapping resolution bandwidth frames, where each frame is processed separately through DFT. By controlling the overlap degree between frames, the system can achieve continuous video bandwidth resolution values, transforming the discrete trace averaging approach into a continuous adjustable system.
Solution Approach 2:
The system dynamically adjusts the overlap degree between consecutive resolution bandwidth frames to achieve different video bandwidth values. This dynamic parameter adjustment allows the DFT-based spectrum analyzer to emulate various video bandwidth filtering effects, providing continuous VBW resolution rather than fixed discrete values.
2Measurement precision
If more spectrum traces are averaged to improve video bandwidth resolution, then noise reduction improves, but measurement time increases
Solution Approach 1:
Multiple resolution bandwidth frames are collected and prepared in advance with appropriate overlapping, allowing the system to perform efficient batch processing through DFT. This preliminary collection of frames enables subsequent fast computation of averaged spectrum traces, reducing the overall measurement time while maintaining noise reduction performance.
Solution Approach 2:
The traditional mechanical sweep-based averaging approach is replaced with digital signal processing techniques including overlapping frame DFT and spectral averaging. This substitution enables parallel processing of multiple frames and achieves faster computation, reducing measurement time while improving video bandwidth resolution through efficient digital algorithms.
3Measurement precision
If discrete number of spectrum traces are used for averaging, then computational complexity is reduced, but video bandwidth resolution becomes coarse
Solution Approach 1:
The system changes the parameter of frame overlap degree to achieve continuous video bandwidth resolution. By varying the overlap parameter between frames, the effective number of averages can be continuously adjusted, providing fine-grained video bandwidth resolution control without requiring a proportional increase in computational complexity.
Solution Approach 2:
Instead of increasing the number of traces in one dimension, the system introduces the overlap degree as an additional dimension for control. This allows achieving higher video bandwidth resolution by utilizing the overlap parameter space, effectively transforming a one-dimensional problem (number of traces) into a two-dimensional solution space (number of traces × overlap degree).
Data Source
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AI summary
A method and apparatus for improved video bandwidth resolution in DFT-based spectrum analysis is disclosed. A first embodiment comprises an emulation of a continuous range of video bandwidths in DFT-based spectrum analysis using overlapping resolution bandwidth frames. A second embodiment utilizes frame weighting to reduce the standard deviation in the spectrum of noise signal to emulate a corresponding standard deviation of a specified video bandwidth.