发明名称 |
Digital modulators for use with sub-nyquist sampling of raster-scanned samples of image intensity |
摘要 |
Apparatus useful in electronics for the tape recording of a video signal, which is a baseband signal of a prescribed bandwidth extending up to a prescribed maximum frequency, processes the video signal to generate a folded-spectrum video signal. The video signal is digitized and supplied to a digital band-splitting filter with a cross-over frequency at one-half said prescribed maximum frequency, for separating the digitized video signal into samples of a lower-frequency-band component and into samples of a higher-frequency-band component. A balanced modulator is connected for modulating a folding carrier wave of the prescribed maximum frequency, which modulation is done in accordance with the higher-frequency-band component to generate a balanced modulation signal; and the balanced modulation signal is linearly combined with the lower-frequency-band component to generate the folded-spectrum video signal. Preferably, the sampling rate of the digitized video signal is exactly the Nyquist rate of the prescribed maximum frequency, reduces the balanced modulation of a suitably phased folding carrier wave to multiplication of successive samples of the modulating signal alternately by plus one and by minus one. Such multiplications are done without having to use a digital multiplier.
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申请公布号 |
US5576837(A) |
申请公布日期 |
1996.11.19 |
申请号 |
US19940296796 |
申请日期 |
1994.08.26 |
申请人 |
SAMSUNG ELECTRONICS CO., LTD. |
发明人 |
STROLLE, CHRISTOPHER H.;WECKENBROCK, HERMANN J. |
分类号 |
H04N5/93;H04L27/00;H04N5/76;H04N5/92;H04N7/12;H04N9/78;H04N9/797;H04N9/80;H04N9/82;H04N9/83;H04N9/835;H04N9/84;H04N9/898;(IPC1-7):H04N9/79;H04N11/04;H04N11/02 |
主分类号 |
H04N5/93 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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