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Color carrier initiation phase recovery method based on DFT interpolation

A phase recovery, carrier technology, applied in color TV, color TV parts, electrical components, etc.

Inactive Publication Date: 2011-02-09
NANJING UNIV
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  • Application Information

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Problems solved by technology

The implementation of the open-loop method is very simple, but because the least mean square fitting algorithm uses the idea of ​​the least square method, it needs to solve the overdetermined equation, so matrix operations are required, which is not suitable for hardware implementation, and software implementation is also time-consuming

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  • Color carrier initiation phase recovery method based on DFT interpolation
  • Color carrier initiation phase recovery method based on DFT interpolation
  • Color carrier initiation phase recovery method based on DFT interpolation

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Embodiment Construction

[0034] The application block diagram of the algorithm in the present invention in the color digital video decoding system is as figure 2 shown.

[0035] 1. If figure 2 As shown, according to the timing of the video signal, the color burst gate pulse of each row is obtained as the enable signal 4 of the color burst extraction module 5, and the starting position of the enabling signal 4 should be more than one cycle away from the starting position of the color burst. 64 sample points are synchronized.

[0036] 2. If figure 2 As shown, the 2 output DFT calculation 6 is performed on the color burst signal, that is, the 6th and 7th DFT coefficients are calculated in parallel with four multiply-accumulators.

[0037] 3. If figure 2 As shown, the obtained coefficients are then interpolated by the linear interpolation calculation module 7 to obtain the starting phase 8 of each color burst, and the calculation process is shown in the third part.

[0038] 4. If figure 2 As sh...

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Abstract

A color carrier initial phase recovery method based on DFT interpolation is disclosed, (1) extracting 64 sample points of undistorted waveform color sync signal; (2) using DFT transformation to calculate the DFT coefficients of the sixth and the seventh discrete frequency points; (3) using linear interpolation to calculate initial phase: the frequency spectrum has the linear interpolation, and the number of the color synchronous sample points is two to the power of an integer, 64 being the optimum value; calculating two DFT coefficients and directly adopting the DFT transformation. The invention is applied to high-precision color hue demodulation by using the two DFT coefficients needed by multiply accumulator calculation and then recovering the initial phase of the local color carrier signal by means of the linear interpolation without using a color carrier recovery phase-lock loop or matrix manipulation in the condition of carrying out digital color decoding of video signal, therebyhaving the advantages of simple structure, convenient implementation, rapid calculation, wide application, etc.

Description

1. Technical field [0001] The invention relates to a technique for extracting the initial phase of a color carrier synchronous signal by using a DFT (discrete Fourier transform) interpolation method. 2. Background technology [0002] The purpose of video decoding is to decompose the full TV signal into five component signals of R, G, B, line synchronization and field synchronization for display on a TV or monitor. In order to obtain color signal components, it is necessary to restore the local color carrier through the color burst signal. When restoring the color carrier, the usual method is to use an analog color carrier phase-locked loop or a digital signal processing method. Among them, the analog phase-locked loop method has been gradually replaced by the digital method due to many factors such as complex components and large volume. The digital recovery system has the advantages of simple structure and high precision. There are two main ways to realize it: the closed...

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04N9/45
Inventor 沈庆宏肖波都思丹韩涛黄勇才
Owner NANJING UNIV
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