• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    Invention m. used for demodulation of color signals in the SECAM television system. The purpose of the invention is to reduce frequency distortion. The device contains a band-pass filter, a sampler 2, an ADC 3, elements 4. and 5 delays per time t 1 / 4F, where F is any frequency value from the frequency band of the frequency-modulated signal, averager 6, two calculator 7 and 9, the delay unit 8 at time 4 T, the memory block 10, the multiplier 11. The calculator 7 contains two accumulators 12 and 13, the computing unit 14, to determine 15 characters, the CO adder 16 and the switch 17, 1 C. P. f-ly.
    公开号:SU1281185A3
    申请号:SU813322052
    申请日:1981-08-12
    公开日:1986-12-30
    发明作者:Ив Морейон Жан
    申请人:Томсон-Цсф (Фирма)；
    IPC主号:
    专利说明:

    to
    00
    This invention relates to television technology and can be used to demodulate color signals in a SECAM television system. The purpose of the invention is to reduce the frequency of the claim, 1x. The drawing shows an electrical circuit of a demodulator of a frequency-modulated signal. A demodulator of a frequency-modulated signal contains a band-pass filter 1, sampler 2, analog-digital converter 3, first and second delay elements 4 and 5 at time T 1 / 4F, where F is any frequency value from the frequency-modulated frequency band, equalizer 6, the first calculator 7, the third delay element 8 at a time of 4 t, the second calculator 9, the memory block 10 and the multiplier 11. The first calculator 7 contains the first and second drives 12 and 13, the computing block 14, the determinant 15 characters, the adder 16 and switch 1 demodulator frequency-mode lied signal works as follows. The SECAM video signal is filtered using a band-pass filter 1 to extract the chroma signal. The signal is then transmitted through the sampler 2 at a frequency of 4F to the analog-to-digital converter 3, from which output the digital values are fed to the first and second delayed elements 4 and 5 sequentially connected. The demodulation of the chroma signal of the SECAM system is reduced to determining the frequency of a sinusoid varying in the 0.8 MHz band with its center at the frequency F equal to 4.3 MHz. Analog-to-digital converter 3 with a frequency of 4F generates digital values of the signal x (t), which can be represented as: x (t) cost2TT (F + 8F) t + 4 cos e (t). Signals delayed by 1 / 4F and 2 / 4F, resulting at the output of delay elements 4 and 5, are respectively: x (t - -) (F +. SF) t- | -. sinLe (t) x (t - 1) - (t) -7T-- | j. Taking 0 (t) e (t) - |. | You can get: x (t) cosle (t) + | - | j; x (t) sine (t) x (t); x (t-- | -)) -2.S | J. The average between x (t) and x (t - -) is taken into account in the averager 6 and has x (t) - x (t - -2 -.-) y (t) <cose (t) - cos I - | .. Assuming that, it is possible to subtract the estimated value 9 (t) of the angle t) using the formula: t) arct t ht /. arctg COS (2 -p) This operation is performed by the first executor 7, using the in-one rolls x (t) and y (t), remembered by carriers 13 and 12 for a time of 1 / F. Vyselitelny block 14 produces the extraction of the value 9 (t) arctg -.The switch 17 connects to the output of the calculator the output of the computational block 14, on which the value 6 (t) is formed, or the output of the sum, which forms the value (t) i TC. Selection of matching
    the position of the switch is carried out by the determiner 15 of the sign depending on the sign y (t).
    权利要求:
    Claims (2)
    [1]
    Two values of the angle e (t) and 1 9 (t -), acting respectively at the outputs of the third delay element 8 and the first calculator 7, allow the second calculator 9 to determine the value of the frequency deviation: ЛР. C + 1) -0-. (T,). In block 10 of the memory, corrections 1 -, are recorded, which, depending on the signals uF and 0 (y-), are received at the second input of the multiplier 11. As a result, the final frequency deviation is obtained at its output: LR (1 -) - 6 F,. Claims 1. A demodulator of a frequency-modulated signal containing a sequentially connected sampler and an analog-to-digital converter, as well as the first calculator, which is 1281185.
     due to the fact that, in order to reduce frequency distortions, the first and second delay elements 1ty are connected in series with the delay time f, 2-7 ;; where F is any frequency value from the frequency-modulated signal frequency band, and an averager whose output is connected to the first input of the first calculator, the third delay element and the second calculator connected in series, the second input of the averager combined with the input of the first delay element and connected to the analogue digital output converter, the output of the first delay element is connected to the second input of the first calculator, the output of which is connected to the input of the third delay element and to the second input of the second Itel.
    [2]
    2. A demodulator according to claim 1, characterized in that a serially connected memory block and a multiplier are entered into it, the second input of which is connected to the output of the second calculator and the first input of the memory block, the second input of which is connected to the output of the first calculator.
    类似技术:
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    同族专利:
    公开号 | 公开日
    FR2488755B2|1982-10-01|
    EP0046103A1|1982-02-17|
    JPS5754488A|1982-03-31|
    FR2488755A2|1982-02-19|
    EP0046103B1|1984-04-18|
    AT7190T|1984-05-15|
    DE3163209D1|1984-05-24|
    US4455533A|1984-06-19|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    FR29376E|1923-12-13|1925-07-25|New fabric and its manufacturing process|
    US4090145A|1969-03-24|1978-05-16|Webb Joseph A|Digital quadrature demodulator|
    JPS4840649B1|1969-09-12|1973-12-01|
    US3956623A|1974-10-21|1976-05-11|Gte Automatic Electric Laboratories Incorporated|Digital phase detector|
    DE2833335C2|1978-07-29|1990-06-21|Telefunken Systemtechnik Gmbh, 7900 Ulm, De|
    FR2469824B1|1979-11-14|1982-04-30|Thomson Csf|DE3212054C2|1982-04-01|1991-02-21|Blaupunkt-Werke Gmbh, 3200 Hildesheim, De|
    FR2535462B1|1982-10-29|1985-02-01|Labo Electronique Physique|
    DE3275448D1|1982-11-26|1987-03-19|Itt Ind Gmbh Deutsche|Digital fm demodulation circuit|
    US4547737A|1983-07-29|1985-10-15|Rca Corporation|Demodulator of sampled data FM signals from sets of four successive samples|
    FR2591048B1|1985-11-29|1988-01-15|Trt Telecom Radio Electr|DIGITAL FREQUENCY DISCRIMINATOR, AND APPLICATION TO A VOR COMPOSITE SIGNAL|
    FR2595895B1|1986-03-13|1988-05-13|France Etat|DUAL DIGITAL DEMODULATOR|
    JPS6448504A|1987-08-18|1989-02-23|Mitsubishi Electric Corp|Fm demodulator|
    US4910469A|1989-05-02|1990-03-20|Rca Licensing Corporation|Demodulator for sampled data FM signals|
    GB9319728D0|1993-09-24|1993-11-10|Snell & Wilcox Ltd|Video signal processing|
    US6031418A|1998-11-19|2000-02-29|Lockheed Martin Corporation|Method and apparatus for demodulating digital frequency modulationsignals|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    FR8017840A|FR2488755B2|1980-08-13|1980-08-13|
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