RU2103839C1 - Digital color television system - Google Patents

Abstract

FIELD: radio communication, digital television broadcasting in decimeter wave range with reception by individual digital TV sets. SUBSTANCE: system has on transmitting side color signal pickup, coding matrix, four analog-to-digital converters, generator of sinusoidal oscillations, frequency divider, encoder, former of group signal and transmitter and on receiving side digital TV set incorporating unit receiving full TV signal, amplitude detector, two pulse formers, brightness signal channel, channels of first and second color-difference signals, audio signal channel, units identifying synchronization code and synchronization of generator of digitization pulses, color kinescope and units providing for operation of kinescope by analog signals. Band of occupied frequencies is determined by stability of day deviation of frequency of generator of sinusoidal oscillations at transmitting side. With day deviation of frequency 10^-6 band of frequencies occupied by 38 channel ( 607.5 Mhz ) amounts to 1215 Hz ( ±607.5 Hz ). Speed of transmission of digital information in this system is 243 Bit/s. Band of frequencies occupied by television channel during broadcasting diminishes 5.10⁴ times as compared with prototype which allows digital television broadcasting in decimeter wave range to be carried out with reception by individual digital TV sets. EFFECT: diminished frequency band used for digital television broadcasting. 1 cl, 7 dwg

Description

 The invention relates to radio communications technology and can be used for digital television broadcasting in the decimeter wave range with reception on individual digital receivers.

 A known analogue is a digital television system for transmitting color images with separate coding of the luminance signal and color difference signals using the differential PCM method with preliminary conversion of the input signals to digital form [1]. On the transmitting side, the signals from the output of the photoelectric converter are fed to the inputs of the shaper of the luminance signal and two color-difference signals, to the outputs of which analog-to-digital converters (ADCs) are connected, while the outputs of the ADCs of color-difference signals are connected to the switch inputs of two color-difference signals in one direction, to the control the input of which is fed through the DPCM encoder to one of the inputs of the multiplexer, the other input of which is connected through the other encoder to the ADC output ala luminance output from the multiplexer full television (TV) signal to the serial code supplied to the transmission input means.

 On the receiving side, a full TV signal from the output of the receiving means is fed to the input of the demultiplexer, one of the outputs of which is connected through the decoder of the DIKM device to the input of the digital-to-analog converter (DAC) of the brightness signal, and the other output is connected through the other decoding device to the input of the color-difference signal switch in two directions , to the control input of which line frequency pulses are applied. From the outputs of the switch, color difference signals are applied to the corresponding DACs. Analog signals from three DACs are used in known image reproducing devices.

 The disadvantage of the analogue is the large occupied frequency band of the TV channel, 120 MHz [2 p. 129].

 The prototype adopted the "Color Television System" by ed. St. N 1040625 [3], which on the transmitting side contains a series-connected photoelectric converter, a shaper of a luminance signal and two color difference signals, a first ADC (luminance signal), a digital low-pass filter, a first inhibit block, a third switch of two signals in one direction, a luminance signal encoder , a multiplexer and a complete TV signal transmission unit, and also contains on the transmitting side a second and third ADC of color-difference signals, the outputs of which are connected to the switch of two signals in one direction, the output is Or, through the second inhibit block and the color-difference signal encoder, it is connected to the second input of the multiplexer, and the second inputs of the first inhibit block, of the second and third ADCs are supplied with color-difference sampling pulses, line frequency pulses are fed to the third input of the third switch, and the third input of the first switch are fed pulses of the frequency of the lines, and on the receiving side contains a series-connected unit for receiving a full TV signal, a demultiplexer, a decoder of the brightness signal, the fourth switch, a digital filter LF, comb filter, OR element, and the first DAC of the luminance signal, the second output of the demultiplexer is connected to the input of the shift register, the output of which is connected to the input of the shift register, the output of which is connected to one input of the fifth switch, two signals in one direction, the second input of which is connected to the second output of the demultiplexer, and the output through the color-difference decoder is connected to the second switch of one signal in two directions, the outputs of which are connected to the second and third DACs.

 The disadvantages of the prototype: although the prototype decreases the throughput of the system by the amount of transmission of color difference signals, i.e. twice, it remains still large up to 60 MHz, and there are no technical solutions for the transmission of sound in digital representation.

 The purpose of the invention is the reduction of occupied bandwidth in digital television broadcasting.

) раз против прототипа и в 6584 раза прототип существующей аналоговой системы телевещания (8•10⁶ Гц/1215 Гц) осуществить цифровое телевещание в диапазоне дециметровых волн и производить прием цифровых телепрограмм непосредственно на индивидуальные цифровые телеприемники.The fulfillment of the goal allows: to reduce the occupied frequency band in the air channel by 5 • 10 ⁴ (

) times against the prototype and 6584 times the prototype of the existing analogue television broadcasting system (8 • 10 ⁶ Hz / 1215 Hz) to carry out digital television broadcasting in the decimeter wave band and receive digital television programs directly to individual digital television sets.

занимаемая полоса на 38 телеканале составляет 1215 Гц (±607,5 Гц). В заявляемой системе согласно требованиям Рекомендации 601 MKKP [4 с.90] приняты:
основной студийный стандарт 4:2:2,
частота дискретизации сигнала яркости 13,5 МГц,
частота дискретизации каждого цветоразностного сигнала 6,75 МГц,
уровней квантования 255, коды представляются 8-бит словами,
кодирование раздельное, методом линейной ИКМ.The reduction of the occupied frequency band is achieved by modulating the carrier frequency in amplitude with positive and negative half-cycles of the sinusoid of the monofrequency of the master oscillator, the half-sinusoids of which represent the signals of the units of the codes of the brightness signal, two color-difference signals and a sound signal. Therefore, the occupied frequency band is determined only by the daily stability of the frequency deviation of the master oscillator, which is a generator of sinusoidal oscillations with a frequency of 121.5 MHz. With a daily frequency deviation of 10 ^-6

the occupied band on 38 channel is 1215 Hz (± 607.5 Hz). In the inventive system in accordance with the requirements of Recommendation 601 MKKP [4 p.90] adopted:
basic studio standard 4: 2: 2,
sampling frequency of the luminance signal 13.5 MHz,
sampling rate of each color difference signal 6.75 MHz,
quantization levels 255, codes are represented in 8-bit words,
separate coding, linear PCM method.

 In FIG. 1 shows a block diagram of a transmitting part; in FIG. 2 - sequence of codes of samples of a line; in FIG. 3 is a block diagram of an ADC of a luminance signal and color difference signals; in FIG. 4 is a block diagram of an ADC audio signal; in FIG. 5 is a structural diagram of a group signal former; in FIG. 6 is a structural diagram of a digital television receiver - the receiving side; in FIG. 7 is a block diagram of a block for receiving a full TV signal.

, формирователь 2 сигнала яркости и двух цветоразностных сигналов, представляющий собой кодирующую матрицу, первый АЦП 3 сигнала яркости, второй АЦП 4 первого цветоразностного сигнала, третий АЦП 5 второго цветоразностного сигнала, четвертый АЦП 6 сигнала звука, последовательно соединенные генератор 7 синусоидальных колебаний (121,5 МГц) и делитель 8 частоты, шифратор 9, формирователь 10 группового сигнала и передатчик 11 полного ТВ сигнала, выполненного в составе последовательно соединенных генератора 12 несущей частоты, амплитудного модулятора 13 и выходного усилителя 14.The transmitting side includes (Fig. 1) a series-connected photoelectric converter 1, which is a color TV signal sensor comprising three primary color signals

, a shaper 2 of the luminance signal and two color difference signals, which is a coding matrix, the first ADC 3 of the brightness signal, the second ADC 4 of the first color difference signal, the third ADC 5 of the second color difference signal, the fourth ADC 6 of the sound signal, the sinusoidal oscillation generator 7 connected in series (121, 5 MHz) and a frequency divider 8, an encoder 9, a group signal shaper 10 and a full TV signal transmitter 11 made as a part of a carrier frequency generator 12 connected in series, an amplitude modulator 13 and output amplifier 14.

 ADC 3 - 5 are made almost identically (Fig. 3).

The ADC 3 is made up of a video amplifier 15, an adder 16, to the second input of which synchronization signals E _si , a piezoelectric deflector 17 with a light reflector at the end, a pulsed emitter as a part of a pulsed LED 18, an aperture 19 and a lens 20, a quantizing line of 21 LEDs, input ends which are optically connected to the light reflector of the piezoelectric deflector 17, and series-connected unit 22 of the photodetectors and encoder 23. To coordinate the work in time, a key 24 is turned on.

 ADC 4 is made up of a video amplifier 25, a piezoelectric deflector 26, a pulsed emitter composed of a pulsed LED 27, a slit diaphragm 28, and a lens 29, a quantizing line of 30 LEDs, a series of photodetector units 31 and an encoder 32 connected in series, and a frequency divider 33 is included for coordinating operation over time :one. The ADC 5 is made up of a video amplifier 34, a piezoelectric deflector 35, a pulsed emitter composed of a pulsed LED 36, a slit diaphragm 37, and a lens 38, a quantizing line of 39 LEDs and a series-connected unit 40 of photodetectors and an encoder 41, a delay element 42 is included for coordinating operation over time ( 74 ns). The ADC 6 of the sound signal includes (Fig. 4) a serially connected controlled voltage divider 43, a block of keys 44, a matching amplifier 45, an amplifier 46 of sound frequency, and a piezoelectric deflector 47 with a light reflector at the end, it contains a pulsed emitter comprising a pulsed LED 48, a slit diaphragm 49 and a lens 50, a quantizing line of 51 optical fibers, serially connected to a block 52 of photodetectors, a first decoder 53, an encoder 54 and a second decoder 55, includes a block 56 of registers connected in series to the first key 60, first Tel frequency 57 860: 1, second switch 58 and a shift register 59, and the second frequency divider 61 288: 1. The input of the ADC 6 is the input of block 43, the control input is the connected inputs of the first and second keys 60, 58 and the second divider 61. The outputs of the ADC are the outputs of block 56 to the driver 10, the fourth output of the shift register 59 to blocks 9 and 24, and the output of the first divider 57 to block 24.

 The group signal generator 10 includes (Fig. 5) four channels, each of the first three consists of a block of 62 (65, 68) AND elements and a first OR element 63 (66, 69) connected in series and includes a pulse distributor 64 (67, 70) , the fourth channel contains a block of elements 71 AND, the first and second elements OR 72, 73 and the distributor 74 pulses. In addition, the driver includes the third and fourth elements OR 75, 77 and two output keys 76, 78.

 The shaper 1O input is the first inputs of the AND elements of blocks 62, 65, 68, 71, the control inputs are the combined inputs of the pulse distributors 64, 67, 70, 74 and the combined inputs of the output keys 76, 78. The output is the combined output of the output keys 76, 78 in block 1Z.

 The receiving side, a digital television receiver, includes (Fig. 6) a serially connected receiver unit 79 for a full TV signal and a bipolar amplitude detector 80, a first pulse shaper 81, a counter 83, an element 84, through an diode connected to the control inputs of the bits of the counter 83 , a pulse-phase-locked loop (IFAP) block 85, a 13.5 MHz sampling pulse generator 86, a frequency multiplier 87 (121.5 MHz), includes a luminance signal channel consisting of a first key 94, a first output register a 88 and the first DAC 107, the channel of the first color-difference signal, consisting of the second key 97, the second output register 90 and the second DAC 109, the channel of the second color-difference signal, consisting of the third key 96, the third output register 89 and the third DAC 108, the sound channel, consisting of the fourth and fifth 95, 98 keys, two blocks of registers 91, 92 and the fourth DAC 110, contains a second pulse shaper 82, serially connected the sixth key 99, the first frequency divider 10O, the seventh key 101 and the shift register 1O2, connected in series to the second divider I03 and the delay element 105 (74 ns), the third divider 104 (289: 1), the eighth key 106 and the element NOT 93. \\\ Next, the known hardware for reproducing the image and sound used in existing analog television receivers is presented in FIG. 6 with the following blocks: video amplifier 116, clock selector 117, horizontal and vertical scanning unit 118 and color picture tube 119, as well as decoding matrix 120, video amplifiers 121, 122, 123 of the first, second and third color-difference signals, sound channel block 124 and loudspeaker 125 .

 Block 79 receiving a full TV signal is made up of (Fig. 7) an input circuit representing a block of filters 111 of concentrated selectivity by the number of received programs, a first radio frequency amplifier 112, a block of band-pass filters by the number of PSIs, a second radio frequency amplifier 114 and AGC block 115 [ 2 c. 143].

The photoelectric converter 1 generates three signals of three primary colors for the luminance signal generator 2 and two color difference signals, which is an encoding matrix that yields the luminance signal E ' _y from the first output, the first color difference signal from the second output, and the second color difference signal from the third output . The ADC 3 converts the luminance signal into an eight-bit code. The ADC 4 converts the first color difference signal into an 8-bit code, the ADC 5 converts the second color difference signal into an 8-bit code. The ADC 6 converts the sound signal into 16-bit codes.

 Shaper 1O of the cargo signal is designed to form four parallel digital streams (Fig. 5) from the ADC of one group signal that produces amplitude modulation of the carrier frequency, and to replace the representation of unit symbols from pulses with positive and negative half-sine waves.

 Shaper 10 consists of four channels. The first channel includes a block of 62 And elements, an And 63 element and a pulse distributor 64, converts the parallel codes of the luminance signal from the 1st to 860 samples from the ADC 3 into serial.

 The second channel includes a block of AND 65 elements, an OR 66 element, and a pulse distributor 67, converts the parallel codes of the first color-difference signal (even samples 2 through 720) from ADC 4 into serial ones.

 The third channel includes a block of AND 68 elements, an OR 69 element, and a pulse distributor 70, converts the parallel codes of the second color-difference signal (odd samples 3 through 719) from ADC 5 into serial ones.

 The fourth channel includes a block of elements And 71, the first and second elements 72, 73 and a pulse distributor 74, converts three codes of the sound signal from the ADC 6 (861, 862, 863 samples) and the code from the encoder 9 (864 samples) into serial ones.

 The third OR element 75 and the output key 76 replace the representation of units in the brightness signal codes, in eight bits of the sound signal codes and in 9 bits of the synchronization code from pulses to positive half-sine waves and combine these codes into one stream.

 The fourth element 77 and the output key 78 replace the representation of units in the codes of the first and second color-difference signals and in eight bits of codes of the sound signal from pulses to negative half-sine waves and combine these codes into one stream.

 The encoder 9 is designed to issue a synchronization code, consisting of nine character units, at the moment of 864 counts in each lad.

Generator 7 of sinusoidal oscillations acts as a master oscillator and generates sinusoids with a frequency of 121.5 MHz with a daily frequency stability of 10 ^-6 .

 The frequency divider 8 divides the frequency of the generator 7 in a ratio of 9: 1 for the ADC 3 and 6 and the driver 10 and 1: 1 for the driver 1O and the transmitter 11. The transmitter 11 generates a radio signal and radiates it to the air. The carrier frequency generator 12 is a frequency multiplier of the generator 7 by "n", where n = 5 ... 1O. In this case, n = 5, i.e. the carrier frequency is 6O7.5 MHz (121.5 MHz • 5).

 The receiving side (Fig. 6) performs the functions of an individual television receiver and carries out the full TV signal, amplifies it, detects it, splits the digital group stream into two, allocates a synchronization code, pulse-phase self-tuning of the sampling pulse generator frequency 86, separates the brightness signal codes, the first and second color difference signals and sound signal through its channels, converting them into analog signals and reproducing image and sound.

 Reception of a full TV signal and its amplification is performed by block 79 according to the direct amplification scheme (Fig. 7). The amplified signal is detected and the digital stream is divided into two by a bipolar amplitude detector 80, which emits 121.5 MHz positive half-sine waves at the first output and negative half-sine waves of the same frequency at the second output.

 The first pulse shaper 81 from positive half-sine waves generates pulses of positive polarity, replaces the representation of units in codes from positive half-sine waves with pulses.

 The second pulse shaper 82 from negative half-sine waves generates pulses of positive polarity, replaces the representation of units from negative half-sine waves with positive pulses. The duration and amplitude are equal to the same pulses on the transmitting side. The synchronization code is allocated by a four-digit counter 83, the AND 84 element and the HE 93 element. A diode included in the communication line between the AND 84 element and the control inputs of the counter 83 eliminates the influence of the signal from the output of the HE 93 element on the operation of block 85 and the key 99. Pulse-phase the frequency control of the generator 86 sampling pulses is performed by the IFAPCH block 85 by pulses from the And 84 element. Separation of the signal codes by their channels is performed by the sixth key 99, the first frequency divider 100, the eighth key 106, the second divider 103, delay element 105, seventh oh key 101 and shift register 102.

 Separation is performed by opening the channel keys at the corresponding time points for the corresponding duration.

 The luminance channel consists of a first key 94, a first output register 88, and a first DAC 107. The first color difference channel includes a second key 97, a second output register 90, and a second DAC 109.

 The channel of the second color difference signal includes a third key 96, a third output register 89 and a third DAC 108.

 The sound channel includes the fourth and fifth keys 95, 98, two blocks of registers 91, 92 and the fourth DAC 110.

 After power is received on the receiving side, all keys are in a closed state.

 Frequency multiplier 87 provides output registers 88, 89, 90 and register blocks 91, 92 with 121.5 MHz clock signals.

 The third divider 104 generates output signals from blocks 91, 92 of the DAC codes 110.

 The conversion of the codes into analog signals is performed by the DAC 107 (luminance signal), 108 (second color-difference signal), 109 (first color-difference signal) and 110 (sound signal).

 The video signal 116, the clock selector 117, and the horizontal and vertical scanning unit 118 provide scanning of electron beams in the kinescope 119. The decoding matrix 120 generates three color difference signals amplified by video amplifiers 121, 122, 123 and supplied to the kinescope modulators. And the sound channel unit 124 and loudspeaker 125 produce audio signals.

The clock frequency is set by the generator 7, which is determined by the transmission rate of digital information:
15625 _lines • 864 _samples • 9 _bits = 121.5 MHz
The photoelectric Converter 1 and the driver 2 of the luminance signal and two color difference signals on the transmitting side are the same as in the prototype. On the receiving side of the DAC, the first, second and third 107, 108 and 109 are the same as in the prototype. The blocks of the analog television receiver 116 - 125 (Fig. 6) are shown to describe the operation of the receiving side.

 ADCs 3–5 are identical and have one conversion principle, which consists in scanning the beam from the emitter (Fig. 3) with a piezoelectric reflector along the plane of the input ends of the quantizing optical fiber line. Then, the light pulse is converted by the photodetector of the photodetector block into an electrical signal, exciting the corresponding input bus of the encoder, which generates a code corresponding to the instantaneous value of the input video signal. The conversion is performed in ADC 3 with a sampling frequency of 13.5 MHz supplied to the input of the LED 18. The sampling frequency is set by a frequency divider 8, dividing the clock frequency of 121.5 MHz by 9 (9: 1).

Параметры пьезодефлектора взяты из табл. 2.3 [7 с. 56].The slit aperture 19 (28, 37) and the lens 20 (29, 38) form a beam with a width equal to the diameter of the entrance pupil of the fiber of the quantizing line 21 (30, 39) and 1 mm high to facilitate alignment. The diameter of the entrance pupil of the fiber in the rulers is 0.02 mm. The source of the pulsed emitter adopted infrared pulse diode AL402A, having a rise time of the radiation pulse of 25 ns [5 p. 39], which satisfies with a margin a sampling frequency of 13.5 MHz. The piezoelectric deflector 17 (26, 35) is an end bimorph piezoelectric element with a light reflector at the end [6 p. 192, 194]. The scanning spot has the shape of a rectangle 0.02 x 1 mm. The quantizing line of 21 (30, 39) optical fibers contains 255 optical fibers for encoding the luminance signal and color difference signals with an 8-bit code from 00000001 to 11111111. At a scanning angle of 15 ^{° by the} piezo-deflector, the plane of the entrance pupils of line 21 is 19 mm away from the piezo-reflector:

The parameters of the piezoelectric deflector are taken from the table. 2.3 [7 p. 56].

 A light pulse from each fiber is converted by its photodetector into an electric pulse, avalanche photodiodes with an operating time constant of 10 ns made by microelectronic technology at the output ends of the optical fibers are used as photodetectors [8 p. 56]. The outputs of each photodetector of block 22 (31, 40) are connected to the corresponding inputs of the encoder 23 (32, 41).

The encoder is a two-stage [9 p. 208], with the arrival of a signal at its input, an 8-bit code appears representing the instantaneous value of the input signal. The encoder generates codes from 00000001 to 11111111. The first fiber corresponds to the code 00000001, the second to 00000010, etc., the 255th to 11111111. The ADC conversion time is determined by the response time of the LFD photodetector of 10 ns and the delay time in the encoder of 50 ns and is 16, 6 • 10 ⁶ prev / s, which satisfies a sampling frequency of 13.5 MHz.

 Conversion to ADC 4, 5 is twice as rare, 6.75 MHz. Frequency reduction is performed by a 2: 1 frequency divider 33. From the encoder 32 of the ADC 4 codes are issued synchronously with the issuance of codes of even samples from the ADC 3, the issuance of codes from the encoder 41 of the ADC 5 is synchronous with the issuance of codes of odd samples from the ADC 3 (Fig. 2). This is provided by a delay element 42, delaying the sampling pulse for a duration of 74 ns.

 The sampling pulses in the ADC 3 are received through a key 24, which is opened by a signal from block 59 of the ADC 6 for a period of 1 to 860 samples of the line and is closed for the time of samples 861-864 from block 57 of the ADC 6. Converting the sound signals to 16-bit codes ADC 6 (Fig. 4). During one line, it generates three codes. The conversion principle is the same, but to obtain a greater bit depth, the transfer coefficient of the control divider 43 is changed.

 The divider 43 is a seven-step resistive divider.

 The key block 44 contains seven keys for connecting the corresponding stage of the divider 43 to the matching amplifier 45, which is an emitter follower.

Импульс с фотоприемника поступает на дешифратор 53, с него на шифратор 54. При отсутствии сигнала на входе делителя 43 на вход дешифратора 55 приходит код из одних нулей, и сигнал с первого его выхода открывает первый ключ в блоке 44, определяя коэффициент передачи делителя в 1,0. С ростом сигнала до кода 2¹⁰ появится импульс на втором выходе дешифратора 55, который откроет второй ключ и закроет первый ключ, коэффициент передачи становится 0,5. С появлением на входе дешифратора 55 кода 2¹¹ открывается третий ключ в блоке 44, коэффициент становится 0,25. При коде 2¹² коэффициент 0,125 и т.д., а при коде 2¹⁵ коэффициент становится 0,015625, который остается до кода 2¹⁶. При уменьшении амплитуды входного сигнала процесс идет обратный. Единицы в кодах представляются наличием импульса, нули - их отсутствием. За время длительности строки шифратор 54 формирует три кода в 16 разрядов. Это обеспечивается делителем 61 частоты, который делит частоту дискретизации 13,5 МГц в отношении 288:1. Коды с шифратора 54 поступают в блок 56, содержащий три регистра. В процессе поступления коды сдвигаются из регистра в регистр импульсами с делителя 61, а после 860-го отсчета выдаются тремя сигналами выдачи, соответствующими моментам 861, 862, 863 отсчетов, со сдвигового регистра 59 в формирователь 10. Формирование сигналов выдачи выполняется вторым ключом 58, первым ключом 60 и первым делителем 57 частоты 860:1. При открытом ключе 60 на вход делителя 57 идут импульсы с делителя 8 частоты. С приходом 860-го импульса делитель 57 открывает ключ 58 и закрывает ключ 60. На вход делителя 57 импульсы не поступают, а через второй ключ 58 на вход сдвигового регистра 59 идут импульсы. С первых трех разрядов регистра 59 импульсы выдают три кода подряд из блока 56 и обнуляют их, импульс с четвертого разряда закрывает второй ключ 58, открывает первый ключ 60, открывает ключ 24 в АЦП 3 и обнуляет свои разряды и выдает из шифратора 9 (фиг. 1) код синхронизации. В исходном состоянии первый ключ 60 находится в открытом состоянии.The quantizing line 51 contains 1024 optical fibers, which provides the conversion of the signal into a 10-bit code 2 ¹⁰ . Resolution adopted 10 μV. The coding range of the ruler is 0 - 0.01024 V. For converting signals exceeding 2 ¹⁰ , the first decoder 53, the second decoder 55, the divider 43, and the key block 44 are used. With their use, the coding range is 0 - 0.65536 V (0 , 00001 V • 65536). Entrance pupil plane removed at

The pulse from the photodetector arrives at the decoder 53, from it to the encoder 54. If there is no signal at the input of the divider 43, the code from the zeros arrives at the input of the decoder 55, and the signal from its first output opens the first key in block 44, determining the transfer coefficient of the divider to 1 , 0. As the signal grows to code 2 ^{10, a} pulse will appear at the second output of the decoder 55, which will open the second key and close the first key, the transmission coefficient becomes 0.5. With the appearance of code 2 ¹¹ at the input of the decoder 55, the third key is opened in block 44, the coefficient becomes 0.25. With code 2 ^{12, the} coefficient is 0.125, etc., and with code 2 ^{15 the} coefficient becomes 0.015625, which remains until code 2 ¹⁶ . When the amplitude of the input signal decreases, the process goes the opposite. Units in codes are represented by the presence of an impulse, zeros by their absence. During the duration of the string, the encoder 54 generates three codes in 16 bits. This is provided by a frequency divider 61, which divides the sampling frequency of 13.5 MHz in a ratio of 288: 1. Codes from the encoder 54 are received in block 56, containing three registers. In the process of receipt, the codes are shifted from register to register by pulses from a divider 61, and after the 860th count, three output signals corresponding to moments 861, 862, 863 counts are issued from the shift register 59 to the former 10. The generation of the output signals is performed by the second key 58, the first key 60 and the first divider 57 of the frequency 860: 1. With the key 60 open, pulses from the frequency divider 8 go to the input of the divider 57. With the arrival of the 860th pulse, the divider 57 opens the key 58 and closes the key 60. No pulses are received at the input of the divider 57, and pulses go to the input of the shift register 59 through the second key 58. From the first three bits of register 59, the pulses give three codes in a row from block 56 and zero them, the pulse from the fourth bit closes the second key 58, opens the first key 60, opens the key 24 in the ADC 3 and resets its bits and issues it from the encoder 9 (Fig. 1) synchronization code. In the initial state, the first key 60 is in the open state.

 The encoder 9 represents a single-stage encoder in which only one code of nine units is generated; transmitted to the receiving part as a synchronization code.

Shaper 10 receives in parallel a code of signals from all ADCs and encoder 9 simultaneously on its four channels. In each, the codes enter the first inputs of AND elements (Fig. 5), and the second inputs receive pulses from pulse distributors 64, 67, 70, 74, respectively. All pulse distributors are self-propelled [10 p. 269] and executed according to the scheme [10 p. 274], they automatically distribute the pulses when a single trigger pulse is applied to the input, which is a sampling pulse of 13.5 MHz from divider 8. The first channel converts the parallel code of the luminance signal from the ADC 3 into a serial one, the code pulses of which, having passed its element OR 63 , arrive at the first input of the third element OR 75 at the moments from the 1st to the 860th samples. The second input of the third element OR 75 receives the pulses of the first eight bits of the code of the sound signal at moments 861, 862, 863 samples of the line. Following them, the pulses of the synchronization code from block 9 are received at the same input at the moment of 864 counts. The conversion of codes from the encoder 9 is carried out by the first nine AND elements of block 71 (Fig. 5). Thus, the codes of the luminance signal, the first eight bits of the audio code and the synchronization code serial combined into one stream passing through the third OR gate 75 and through the first output switch 76. Speed information in the first stream: 15625 _rows • 864 • 9 _{bit count} = 121.5 Mbps.

 The second channel of the shaper converts the ADC 4 codes, the pulses of which, having passed their element OR 66, arrive at the first input of the fourth element OR 77 at the moments of even samples from 2 to 720 with a frequency of 6.75 MHz. The third channel of the shaper 10 converts the codes from the ADC 5, the pulses of which, having passed their element OR 69, are fed to the second input of the fourth element OR 77 into the odd samples of the line from 3 to 719 with a frequency of 6.75 MHz. The third input of the OR element 77 receives pulses of codes of the audio signal from the 9th to the 16th digits. Thus, the second, third color difference signals and the second half of the bits of the codes of the sound signal are combined into a second stream passing through the OR element 77 and then through the second output key 78. The information rate is also 121.5 Mbit / s.

 The pulses of codes from the OR elements 75, 77 come to the control inputs of the output keys 76, 78, opening them for the duration of their duration, and the signal inputs of the keys receive sinusoidal oscillations with a frequency of 121.5 MHz from the second output of the divider 8. At the open state, the output key 76 allows only positive half-sine waves to pass through, and a second output switch 78 passes only negative half-sine waves. Thus, the impulses in the codes are replaced by positive and negative half-sinusoids. Output keys 76, 78 are made according to the diode bridge circuit [13 p. 169] with the on time of the unit ns. The outputs of the output keys are connected, therefore, from the output of the shaper 10 there is a sequence of complete and incomplete sinusoids with a frequency of 121.5 MHz, which perform amplitude modulation with a monoharmonic signal of the carrier frequency in the modulator 13 of the transmitter 11. The generator 12 of the carrier frequency is a frequency multiplier of the generator 7 by "n" , where n = 5. ..10, in this case n = 5, so the carrier frequency is 607.5 MHz (121.5 MHz • 5), which corresponds to the 38th broadcasting channel (0.494 m).

), и в 6584 раза меньше, чем у работающей сейчас аналоговый системы (

). Полный телевизионный радиосигнал принимается антенной принимающей стороны - цифровым телеприемником (фиг. 6) и поступает на вход блока 79 приема полного ТВ сигнала. Состав блока 79 дан на фиг. 7. С выхода блока 79 сигнал ТВ идет на двухполярный амплитудный детектор 80. С первого выхода детектора 80 положительные полусинусоиды частотой 121,5 МГц поступают на вход первого формирователя 81 импульсов, со второго выхода детектора отрицательные полусинусоиды поступают на вход второго формирователя 82 импульсов. Формирователи формируют из полусинусоид импульсы положительной полярности и длительности, равной длительности импульсов кодов на передающей стороне. Формирователи импульсов 81, 82 выполнены по схеме несимметричного триггера с эмиттерной связью [12 с. 209], формирующего прямоугольные импульсы из гармонически изменяющихся сигналов. После формирователей единицы в кодах представлены импульсами. С первого формирователя 81 коды поступают на вход счетчика 83, на вход элемента НЕ 93 и на первые входы первого 94 и четвертого 95 ключей.The total information transfer rate is summed up and amounts to 243 Mbit / s, in this volume the brightness signal information is 108 Mbit / s, the first and second color-difference signals are 54 Mbit / s each, the sound signal is 0.75 Mbit / s and the synchronization signal is 0.140625 Mbps The occupied frequency band on the air is 1215 Hz (± 607.5 Hz), which is 49382 times less than that of the prototype (

), and 6584 times less than the current analog system (

) A full television radio signal is received by the antenna of the receiving side - a digital television receiver (Fig. 6) and is fed to the input of the block 79 receiving a full TV signal. The composition of block 79 is given in FIG. 7. From the output of block 79, the TV signal goes to a bipolar amplitude detector 80. From the first output of the detector 80, positive half-sine waves with a frequency of 121.5 MHz are fed to the input of the first driver 81 pulses, from the second output of the detector negative half-sine waves are fed to the input of the second driver 82 pulses. The shapers form pulses of positive polarity and a duration equal to the pulse width of the codes on the transmitting side from half-sine waves. The pulse shapers 81, 82 are made according to the scheme of an asymmetric trigger with emitter coupling [12 p. 209], forming rectangular pulses from harmonically varying signals. After the formers, the units in the codes are represented by pulses. From the first driver 81, the codes are received at the input of the counter 83, at the input of the element NOT 93, and at the first inputs of the first 94 and fourth 95 keys.

 With power on, the sampling pulse generator 86 provides 13.5 MHz pulses. The synchronization of the generator 86 is performed by a pulse-phase self-tuning frequency [11 p. 195] using the IFAPCH block 85, counter 83, and element 84. Counter 83 counts the incoming pulses from the first pulse shaper 81. Any incoming code except for the synchronizing code has eight units at most in a row, therefore, before the synchronization code arrives, the counter 83 will always be reset to zero by the signal from the element NOT 93. When counting nine units of the synchronizing code, 1001 are generated in the digits, and the AND 84 element will give a pulse, according to which the generator is synchronized 86. The pulse for synchronization comes in the 864th sample in each line, therefore, the generator 86 is synchronized with the reception of the first line.

 Conversion of the serial presentation of codes to parallel is performed by filling out the output registers 88, 89, 90 and blocks 91, 92 of the sound registers. The first output register 88 is filled with pulses of the code of the luminance signal that has passed the first open key 94, the second output register 90 with pulses of the code of the first color-difference signal that has passed the public key 97, the third register 89 is filled with code pulses of the second color-difference signal that have passed the open third key 96. block 91 registers are filled with pulses of the first eight bits of the sound code code that passed the fourth key 95, the registers of the second block 92 registers are filled with pulses of the second eight bits of the same code s drove the sound, passing the fifth fifth key 98. The keys 95, 98 are open at the moments 861, 862, 863 samples of the line. Each block 91, 92 contains three registers for receiving consecutive three sound codes. As they arrive, codes move from the first register to the second and third. The control signals come from the first and second bits of the shift register 102. The distribution of codes in their blocks 88 - 92 is carried out by the corresponding opening and closing of the corresponding keys.

 This process is as follows. The synchronization pulse from the output of the AND element 84 opens the sixth key 99, the divider 100 starts counting the new line pulses that come from the generator 86. The divider 100 has two outputs: the first output is 720: 1, the second is 860: 1. The signal from the first output closes the eighth key 106, the sampling pulses do not enter the input of the second divider 103, the third keys 96 and the second 97 are closed, the second and third output registers 89, 90 are protected from sound codes. With the arrival of the 860th pulse, the signal from the second output of the divider 100 closes the first key 94 and sixth 99 and opens the fourth keys 95, fifth 98 and seventh 101. The public keys 95 and 98 pass the codes to the registers of blocks 91, 92. The key 102 passes the sampling pulses to the input of the shift register 102, which has three digits: the signals from the first and second digits move the codes in the registers of blocks 91, 92, the signal from the third digit closes the fourth 95, fifth 98 and seventh 101 keys and opens the first 94 and eighth 106 keys, filling in the signal codes begins bones of the output register 88 and codes of color-difference signals of the output registers 90, 89. Then the process is repeated all the time. After powering up the receiver, all keys are in a closed state. The movement of the code pulses in the bits of the registers 88 - 90 and in the bits of the registers in blocks 91, 92 is performed by pulses of a clock frequency of 121.5 MHz from a frequency multiplier 87.

 The keys 96, 97 are in the open state only for the duration of the sampling pulse duration from the block 103 of the 2: 1 divider and from the delay element 105 (74 ns). Key 97 is open for every even line count, key 96 is open for every odd line count.

 From the output registers 88 - 90, codes are issued in parallel. Codes of the brightness signal are issued by each sampling pulse of the generator 86, codes of color-difference signals are issued simultaneously by the signal from the output of the divider 103. Both parts of the sound code are simultaneously transmitted by the signal from the third divider 104 (288: 1) to the fourth DAC 110. The codes of the brightness signal are converted into analog signals by the first DAC 107, codes of the first color-difference signal by the second DAC 109, codes of the second color-difference signal by the third DAC 108. Next, the analog signals from the DAC are fed to the corresponding blocks of a conventional color TV.

 System operation.

 From the photoelectric converter 1, the voltages of three color-separated signals are supplied to the inputs of the shaper 2 of the luminance signal and two color-difference signals, the output of which is fed to the DAC 3 - 5. The synchronization signal is also fed to the second input of the ADC 3. The ADC 3 converts the total brightness and synchronization signal into 8-bit codes with a frequency of 13.5 MHz. Color difference signals are converted to 8-bit ADC codes 4, 5 with a frequency of 6.75 MHz. In parallel, the ADC 6 converts the sound signals into 16-bit codes with a frequency of 46875 Hz, the sampling frequency is set by the divider 61 (Fig. 4). At the input of the former 10, codes of the luminance signal from the 1st to 860 samples are presented (Fig. 2), codes of the first color-difference signal from the 2nd to 720 are even samples, codes of the second color-difference signal from the 3rd to 719 are odd samples, sound code codes 861 to 863 counts and the synchronization code is the last 864 count of the line. Codes of line and frame blanking pulses of the beam blanking, equalizing pulses and inserts, summed in the adder 16 of the ADC 3 during the inactive part of the line (with the return stroke), are presented from the 721st to 860 samples.

 Shaper 10 group signal receives parallel codes from four ADCs and from the encoder 9, converts them into serial and two streams. In the first stream, codes of the luminance signal, the first eight bits of the sound signal and the synchronization code, the units in them are represented by the positive sinusoids of the monoharmonic signal, in the second stream the codes of the first and second color-difference signals and the second eight bits of the sound signal, the units in them are represented by negative half-sines of the same oscillations from the generator 7.

 The carrier frequency in the transmitter is modulated by a group signal from the shaper 10, which is a whole and non-integer sine wave with a frequency of 121.5 MHz. The generated complete TV signal is amplified by the transmitter 11 and radiated into the air.

 The radio signal is received at the receiving side by the TV signal receiving unit 79, amplified and fed to the input of a half-wave amplitude detector 80. The detected signal is fed: positive half-sine waves to the first pulse shaper 81, negative half-sine waves to the input of the second pulse shaper 82. Having passed the shapers, the units in the codes are represented by pulses of positive polarity, the duration of which and the amplitude correspond to the pulses of units on the transmitting side. With the receiver turned on, the generator 86 generates 13.5 MHz sampling pulses. At the end of each line, the input of the IFAPCH block 85 receives an impulse from the And 84 element, which synchronizes the operation of the generator 86. From the formers 81, 82, the code pulses through the corresponding keys go to their output registers 88, 89, 90 and to the registers of the blocks 91, 92, from where signals are issued to their DACs. The claimed part of the receiving party ends here. Next, the analog luminance signal is fed to the first input of the decoding matrix 120, to the input of the video amplifier 116 and from it to the corresponding input of the kinescope 119. The selector 117 selects the synchronization pulses and outputs them to the horizontal and vertical scanning unit 118. Color-difference analog signals are fed to the inputs of the decoding matrix 120, and amplified in video amplifiers 121, 122, 123, are fed to the color picture tube modulators. The analog sound signal is amplified in block 124 and is reproduced by the speaker.

The technical and economic effect of the claimed system consists in reducing the occupied frequency band during transmission by 56 • 10 ⁴ times against the prototype, 6584 times against the analogue television systems currently in use, and in the possibility of digital broadcasting in the range of decimeter waves to digital individual television sets.

 The inventive system can be used for digital television broadcasting.

Literature
1. NTZ, 1977, 30, N 5.

 2. A. V. Vykhodets and others. “Sound and television broadcasting”, M., 1987, p. 129, 143.

 3. Auth. St. N 1040625 m. H 04 N 11/04 bull. of. N 33, 1983, prototype.

 4. TIIER, t. 73 N4, April 1985, p. 89-90.

 5. Ivanov et al. "Semiconductor optoelectronic devices", reference book, M, 1984, p. 39.

 6. Handbook of laser technology, ed. Bayborodina et al., Kiev, 1978, p. 192, 194 images 13.7 c.

 7. Calculation of elements of laser scanning systems. Dneprovsky et al., Minsk, 1986, p. 56 tab. 2.3.

 8. L.M. Andrushko et al. "Fiber-optic communication lines", M., 1984, p. 56.

 9. V.N. Tutevich "Telemechanics", M, 1985, p. 208.

 10. V.A. Ilyin "Remote control and telemetry", M, 1982, p. 269, 274.

 11. Television, ed. V.E. Dzhakonii, M, 1986, p. 1985.

 12. V.F. Barkan, V.K. Zhdanov "Amplification and impulse technology", M, 1981, p. 209.

 13. Handbook of Automation, ed. V.E.Nize, M., p. 169 images 6.59 a.

Claims (2)

 1. A digital color television system comprising, on the transmitting side, a photoelectric converter and a shaper of a luminance signal and two color-difference signals, serially connected, to the first, second and third outputs of which are connected the first, second and third analog-to-digital converters (ADCs), and a full transmitter television (TV) signal and on the receiving side, a unit for receiving a full TV signal and first, second and third digital-to-analog converters (DACs), characterized in that it has a sine wave generator, a synchronization signal, and a frequency divider, a fourth ADC and an encoder connected in series to the first input of the fourth ADC are provided with a sound signal, the second input is connected to the first output of the frequency divider, the first output of the fourth The ADC is connected in parallel to the input of the encoder and to the fourth input of the first ADC, the third input of which is connected to the first output of the frequency divider, and the fifth input of the first ADC is connected n to the second output of the fourth ADC, the group signal shaper, the first, second, third and fourth inputs of which are connected respectively to the outputs of the first, second, third ADCs and the third output of the fourth ADC, the fifth and sixth inputs are connected to the first and second outputs of the frequency divider, and the seventh input is connected to the output of the encoder, contains four channels, the first three of which are identical and each includes a series-connected block of AND elements and an OR element and a pulse distributor, the first inputs of AND elements are the input inputs of the group signal shaper and are connected to the outputs of the corresponding ADC, the other inputs of the elements AND are connected to the corresponding outputs of the pulse distributor of their channel, the fourth channel includes a block of AND elements, the first and second OR elements and a pulse distributor, and the first inputs of the AND elements, except for the ninth element And, connected to the outputs of the fourth ADC, the same inputs of the first nine elements And are connected to the outputs of the encoder, the second inputs of the elements And are connected to the corresponding outputs of the distribution pulse generator of its channel, the outputs of the first nine AND elements are connected to the inputs of the first OR element, the outputs of the remaining elements AND are connected to the inputs of the second OR element of its channel, the inputs of the pulse distributors of all channels are combined and connected to the first output of the frequency divider, contains the third OR element in series and a first output key and a fourth OR element and a second output key connected in series, wherein the first input of the third OR element is connected to the output of the OR element of the first channel, in the second input of the third OR element is connected to the output of the first OR element of the fourth channel, the first input of the fourth OR element is connected to the output of the OR element of the second channel, the second input of the fourth OR element is connected to the output of the OR element of the third channel, the third input is connected to the output of the second OR element of the fourth channel , the signal inputs of the output keys are combined and connected to the second output of the frequency divider, and the outputs of the output keys are combined and are the output of the driver of the group signal, the transmitter is a full TV the ion signal is made in the form of a signal made in the form of a series-connected carrier frequency generator, the input of which is connected to the second output of the frequency divider, the amplitude modulator, the second input of which is connected to the output of the group signal shaper, and the output amplifier, an amplitude detector and two shapers are introduced on the receiving side pulses, the inputs of which are connected to the first and second outputs of the amplitude detector, a channel of the luminance signal is introduced as part of the series-connected first key and of the output register, the channel of the first color-difference signal as part of the second key and the second output register in series, the channel of the second color-difference signal as part of the third key and the third output register in series, the outputs of the output registers of the luminance signal channels and both color-difference signals are connected to the inputs of the first, second and the third DAC, the sound signal channel in the composition of the fourth key and the first block of registers connected in series, connected in series the fifth key and the second block of registers, the DAC whose inputs are connected to the outputs of the first and second block of registers, the signal inputs of the first and fourth keys are connected to the output of the first pulse shaper, the signal inputs of the second, third and fifth keys are connected to the output of the second pulse shaper, series-connected counter, the input of which is connected to the output of the first pulse shaper, the element And, the inputs of which are connected to the outputs of the highest and lowest bits of the counter, the pulse-phase block automatic frequency locking (IFAPCH), a sampling pulse generator and a frequency multiplier, the outputs of which are connected in parallel to the first control inputs of the output registers of the brightness channel, both color difference signal channels, both blocks of sound channel registers, the sixth, seventh, eighth keys and the third frequency divider (288 1), the inputs of which are connected to the output of the sampling pulse generator, the first control input of the sixth key is connected to the output of the And element, the output of which through a diode is connected in parallel to the control input m of counter bits, the sixth key output is connected to the input of the first divider, the first output of which is connected to the second control input of the eighth key, the second output of the first divider is connected to the second control inputs of the first and sixth keys, to the first inputs of the fourth, fifth and seventh keys, shift register whose input is connected to the output of the seventh key, and the control input is connected to the output of the sampling pulse generator, the outputs of the shift register are connected first to the second control inputs of the first and second block in the sound channel registers, the second to the third control inputs of the first and second blocks of registers, the third to the first control inputs of the first, eighth keys, the second control inputs of the fourth, fifth and seventh keys, the output of the third frequency divider is connected in parallel to the fourth control inputs of both blocks of the channel registers sound, the second input of the IFAPCH unit is connected to the output of the sampling pulse generator, a second frequency divider 2 1 is connected in series, the input of which is connected to the output of the eighth key, and the delay element, the output of which is connected to the control input of the third key, and the output of the second frequency divider is connected to the control input of the second key and to the second control inputs of the output registers of the channels of the first and second color-difference signals, and the element is NOT entered, the input of which is connected to the output of the first pulse shaper and the output is connected in parallel to the control inputs of the bits of the counter, the block for receiving the full TV signal is made up of series-connected block of filters of concentrated selective and the first RF amplifier, bandpass filter unit and the second radio-frequency amplifier, and the AGC unit whose input is connected to the second output of the second RF amplifier and an output connected to the second input of the first RF amplifier.  2. The system according to claim 1, characterized in that the first, second and third ADCs are made in the form of a series-connected video amplifier and a piezoelectric deflector with a light reflector at the end, a pulse emitter, a pulsed LED, a slit diaphragm and a lens, a quantizing line of optical fibers, inputs which are optically connected to the light reflector of the piezoelectric deflector, series-connected block of photodetectors and encoder, the inputs of the block of photodetectors are optically connected to the output ends of the optical fibers of the quantizing line of light Gadgets, the first input of the ADC is the input of the video amplifier, and the ADC output is the encoder outputs, the first ADC includes an adder between the output of the video amplifier and the input of the piezoelectric deflector, the second input of which has synchronization signals and it is the second input of the first ADC, and the key, the first control input of which is the second input of the first ADC, and the key, the first control input of which is the fourth input of the first ADC and the second control input is the fifth input of the first ADC, to the third input of which frequency pulses are applied sampling from the first output of the frequency divider, and the output of the key is connected to the input of the pulse LED, the second ADC includes a frequency divider (2 1), the input of which is connected to the output of the key of the first ADC, and the output is connected to the input of the pulse LED of its ADC, the third ADC includes a delay element whose input is the control input of the third ADC and connected to the output of the frequency divider of the second ADC, and the output is connected to the pulse LED of its ADC, the fourth ADC is made up of a series-connected controlled divider voltage, a key block, a matching amplifier, an audio frequency amplifier and a piezoelectric deflector with a light reflector at the end, a pulsed emitter consisting of a pulsed LED, a slit diaphragm and a lens, a quantizing line of optical fibers whose inputs are optically connected to the light reflector of the piezoelectric deflector, connected in series to the photodetector unit, the first a decoder, an encoder and a second decoder, the outputs of which are connected to the corresponding control inputs of the key block and to the corresponding inputs the first decoder, and the inputs of the block of photodetectors are optically connected to the output ends of the fibers of the quantizing line, and also includes a block of registers, the inputs of which are connected to the outputs of the encoder, and the first key, the first frequency divider, the second key and the shift register, the first, second, third the outputs of which are connected to the first, second and third control inputs of the register block, the fourth shift register output is connected to the second control input of the second key, to the first control input key, to the control input of the shift register itself, and the fourth shift register output is the first output of the fourth ADC, which is connected to the first control input of the key of the first ADC and to the input of the encoder of the transmitting side, the output of the first frequency divider is connected to the second control input of the first key and is the second output of the fourth ADC, which is connected to the second control input of the key of the first ADC, the third output of the fourth ADC are the outputs of the register block, and the input and control input of the fourth ADCs are managed respectively input voltage divider and the interconnected first inputs of the first, second key and input of the second frequency divider, a first output of which is connected to the input of the LED pulse, and the second output is connected to the fourth control input of unit of registers.

Images