SU1284992A2 - Method of detecting frequency- and phase-manipulated signals of digital information reproduced from magnetic medium and device for effecting same - Google Patents

Abstract

The invention relates to magnetic recording and permits a reduction in detection errors by increasing synchronization stability. Shapers 6 and 7 form the first and second, and the element And 5 - the third pulse sequence. Counter 1-0 17, counting the high-frequency pulses of the generator 16 pulses, together with the decoder 18 forms the fourth pulse sequence. The trigger .13 generates a fallout pulse, the falling edge, which is held on trigger 14. The trigger 19, 24, 25, and 10 are zeroed by the pulses of the third, fifth, sixth and seventh sequences and are switched for each pulse of the fourth sequence. The signals from the outputs of the flip-flops 19, 24, and 25 are memorized on the flip-flops 15, 27, and 28. Elements 12, 20, and 21 form the fifth, sixth, and seventh sequences. The clock signal is supplied to the synchronization bus 11. Element And 8 generates pulses of information units,. stepping onto the bus 9, and the element And 22 - impulses of information zeros, zero- g (Л с ю 00 4; а о ND 1Ч

Description

1284992

trigger trigger 26. The trigger 26 forms the pulses of the altimeter markers, rubs the strobe signals, with the help of which the element And 23 forms impinging on the sync bus 2 2 s. apt. / 4 Il.

pulses of atipiroskim markers

Stepping onto a sync bus 29. 2 s. apt. / 4 Il.

one

The invention relates to magnetic recordings, in particular to methods and devices for detecting manipulated in frequency and phase digital information signals reproduced from 5 fertile carriers, and is an improvement of the method and device according to the authors. St. No. 1195376.

The aim of the invention is to reduce the detection error in O due to the increased stability of the synchro-.

FIG. 1 shows the time diagrams explaining the principle of the formation of anti-transverse markers in the original information signal recorded on a magnetic carrier; in fig. 2 - timing diagrams explaining the essence of the method; On fng. S - 20 functional diagram of the device for implementing the method; in fig. 4 - timing diagrams explaining the principle of operation of the device.

In Fig. 1a P9, pens of all possible 25 variants of forming anti-transverse markers in the initial information depending on the code combination in the marker bit (in Fig. 1 is limited by a dotted line) and two adjacent digits.

FIG. 2a shows a signal reproduced from a magnetic carrier, in which there are areas with a reduced amplitude value. To the fixer, the extremums of the reproduced signal, the first pulse sequence is formed (Fig. 2Y. By the fixed levels of the reproduced signal, the second pulse sequence is formed)

complexity (Fig. lb). From the first and second pulse sequences, a pulse is formed (Fig. 1), corresponding to the signal fallout mode, with a duration equal to the interval Vald mezvdu first ;, signal sigma after the beginning and after the end of the fallout mode. Simultaneously form

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the third pulse sequence (Fig. 2a) by multiplying the first and second pulse sequences. Then, for each pulse of the third sequence, form the fourth pulse sequence (FIG. 2e) of the doubled clock frequency and delay it relative to the third pulse sequence for a quarter of the clock period. At the same time, the number of fourth pulse (Fig. 2e) sequence within the intervals between the third pulse (Fig. 2a) sequence and each pulse of the third sequence following the even number of fourth sequence pulses are counted, an auxiliary pulse sequence is formed (Fig. 2). At the same time, the falling edge of the fallout pulse (Fig. 2d) is delayed until the fourth pulse sequence (Fig. 2), which is the first after the dropout mode ends, and forms the fifth pulse sequence (Fig. 2c) by multiplying the auxiliary (Fig. 2g) sequence and pulse ( Fig. 2).

Calculate the number of pulses of the fourth (Fig. 2e) sequence within the intervals between the pulses of the fifth (Fig. 2o) sequence and for each pulse of the fifth sequence following the fourth number of pulses of the fourth sequence, form the sixth pulse sequence (Fig. 2k). This operation is necessary due to the presence in the source information (Fig. 1) of anti-transverse markers formed according to Figs. , 1a, & , B, 7,, i},,.

Count the number of pulses of the fourth (Fig. 2e) sequence within the intervals between the pulses of the sixth (Fig. 2k) sequence

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for each pulse of the sixth postodelnoe, the next “even” number of impulses, the fourth sequence sleep, form the seventh impulse sequence (Fig. 2A). This operation is necessary due to the presence in the initial information of anti-twisted markers formed according to Fig. 1e.

A sync signal (Fig. 2m) is formed by dividing the pulse frequency of the fourth (Fig. 2e) sequence by two times, the specified polarity of the result of the division being set by the seventh pulse (Fig. 2l) 5 of the sequence torus. By multiplying the sync signal (fig, 2m) and the third (fig 2ij), a pulse sequence of units of information symbols (fig, 2h) is formed, which also contains anti-transverse markers.

The sync signal is inverted (in FIG. 2, the result is not shown) and by multiplying the inverse sync signal and the third (FIG. 2a) sequence, form a pulse sequence of information symbols zeros (FIG. 2o),

Count the number of pulses of the fourth (fig, 2e) sequence between pulses of a sequence of zeros (fig, 2o) of information symbols and for each first after three pulses of the fourth sequence a pulse of a sequence of units (fig, 2n) of information symbols form a sequence of anti-transverse markers (fig, 2n),

A device for detecting digital information manipulated in frequency and phase and reproduced from a magnetic carrier contains serially connected magnetic head 1, amplifier 2, filter 3 and rectifier 4 connected by an output to the corresponding inputs of the first element I 5 through drivers 6 and 7 impulses by extremes and signal levels, the output of the first element AND 5 is connected to one input of the second element AND 8, connected by TitiTept .i 13, 14 and t3, g a pulse 16 pulses, a counter 17 pulses, a drift 18 and a second counting igger 19, while the first trigger 13 is connected by synchronization and information inputs to the outputs of the formers 6 and 7, respectively, by extremes and signal levels and the output to the installation input of the second trigger 14 connected by the synchronization input to the synchronization inputs of the second counting trigger 19, third trigger 15 and the first counting trigger 10 and with the output of descramble 18, and the output with the first input of the And 12 element, the second input connected to the output of the third trigger 15, the information input of which is connected to the output of the second counting trigger 19, the installation input connected to the third input of the third element And 12 and connected to the installation input of the counter 17 pulses and the output of the first element And 5, and the third element And 12 connected output to the installation input of the first counting trigger 10, and the counter 17 pulses connected to the input to the output of the generator 16 pulses and the output to the input of the decoder 18,

In addition, a device for detecting digital information signals that are reproduced from a magnetic carrier that is controlled by frequency and phase contains fourth, fifth, sixth, and seventh elements 20, 21, 22, and 23, third, fourth, and fifth counting triggers 24, 25 and 26 and fourth and fifth triggers 27 and 28, while the third element And 12 is connected by an output to the installation input of the first counting trigger 10 through the fourth and fifth elements And 20 and 21 connected in series, the last of which is connected by one of the inputs to the output n addition trigger 28, n Connected by the synchronization input to the interconnected output of the decoder 18 and the synchronization inputs of the fourth one. trigger 25 connected by an output to the information input of the fifth tri1-

thirty

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output bus with information bus 9 „28 and the mouth of the receiver

the output of the fourth element And 20, the fourth trigger 27, connected by output to one of the inputs of the fourth other input - with the output of the first counting trigger 10 and with the synchronization bus -11, and also the third eletrigger to one element H 20,

Ment And 12, the first, second and third

sh

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25

5 torus

849924

TpitiTept.i 13, 14, and t3, r a pulse generator 16 pulses, a pulse counter 17, a digifrator 18 and a second counting trigger 19, while the first trigger 13 is connected by synchronization and information inputs to the outputs of the formers 6 and 7, respectively, at the extremes and signal level and output - to the installation input of the second trigger 14, connected by the synchronization input to the synchronization inputs of the second counting trigger 19, the third trigger 15 and the first counting trigger 10 and the output of the descramble 18, and the output - to the first input of the And 12 terminal, the second input connected go to the output of the third trigger 15, the information input of which is connected to the output of the second counting trigger 19, the installation input connected to the third input of the third element And 12 and to the interconnected installation input of the pulse counter 17 and the output of the first element And 5, and the third element And 12 is connected by the output to the installation input of the first counting trigger 10, and the pulse counter 17 is connected by the input to the output of the generator of 16 pulses and the output to the input of the decoder 18,

In addition, a device for detecting digital information signals that are reproduced from a magnetic carrier that is controlled by frequency and phase contains fourth, fifth, sixth, and seventh elements 20, 21, 22, and 23, third, fourth, and fifth counting triggers 24, 25 and 26 and fourth and fifth triggers 27 and 28, while the third element And 12 is connected by an output to the installation input of the first counting trigger 10 through the fourth and fifth elements And 20 and 21 connected in series, the last of which is connected by one of the inputs to the output n addition trigger 28, n Connected by the synchronization input to the interconnected output of the decoder 18 and the synchronization inputs of the fourth one. trigger 25 connected by an output to the information input of the fifth tri1-

thirty

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the output of the fourth element And 20, the fourth trigger 27, connected by the output to one of the inputs of the quadtrigger to one element H 20,

and the third counting trigger 2 / connected by the installation input to the output of the third element 12 and the output to the information input of the fourth trigger 27, with the test element AND 22 connected by the first input to the auxiliary output of the first counting trigger 20, the second input to the output of the first element 5 and input - to the installation input of the fifth counting tri-fO (Fig. 4). Thus, at the inputs of the switch 26 connected to the synchronizing element I 12 there are signal inputs with the output of the first counting trigger 10 and the output with the first RXO, the house of the seventh element I 23, connecting the outputs of the trigger 15 (phi1.4j), trigger 14 ( Fig. 4 ") and the element And 5 (Fig. 4). If these second signals match the second input, a fifth pulse element AND 8 is formed, a third input to the output of the second trigger 14 and an output to the additional bus 29 synsequence (Fig. 4i). The trigger 24 is zeroed by each pulse of the fifth sequence and is switched for each pulse of the fourth 20 sequence (Fig. 4A).

chronic disease

The proposed device works as follows.

The signal from the output of the trigger 24 for each pulse of the fourth sequence is stored on trigger 2 (Fig. 4 (e). The inputs to the elements of the Reproducible Magnetic Head 1 signal (Fig. 4q) goes to

shaper 6 at the extremes, which is 25 and 20, signals from the output are present, which forms the first pulse sequence of trigger 27 (fig. 4m) and element sequence (fig. 4S), and at shaper 7 according to the levels, which forms the second pulse sequence And 12 (Fig, 4k). When these signals coincide, a pole is formed, a pulse sequence (Fig. 4n), a strength (Fig. 4B). The first sequence 30 Similarly, the trigger 25 is nullified and sent to synchronization with each pulse of the sixth consecutive input of the trigger 13, and the second and switches each to its information input. As a result, the fourth pulse at the output of the trigger 13 is formed - and (Fig. 4o). The signal from the output of the trigger impulse loss (Fig. 4). Per-j, j er 25, for each pulse, the fourth and second sequences also arrive at the inputs of the element 5, which, at the moments of their coincidence, forms the third pulse sequence of the sequence, is remembered at trigger 28 (Fig. 4n). If the signals from the outputs of the trigger 28 (Fig, 4p) and the And 20 element coincide with each other (Fig. 4). For each of them 40 and AND 21, the seventh pulse of this sequence is set to zero and a sequence (Fig. 4p).

The trigger 10 is zeroed in each pulse of the seventh sequence and the count recalculating counter 17 of the selected fourth sequence switches on each pulse. They are formed in such a way that on the code, the detuned by the trigger 10 sync signal of the fractioner 18, which deciphers the specified (. 4c) enters the bus 11, the counted states of the counter 17, for-. synchronization and on one of the inputs of the IW element, at the second input of which 50 there are pulses of the third sequence.

Counter 17 starts counting pulses of a high frequency oscillator 16. Generator frequency .16 and a fourth pulse sequence (Fig. 4e), which enters the clock inputs of the trigger 15 and 19, is triggered. Trigger 19 is zeroed with each pulse of the third sequence and switches each coincidence of these signals on the element And 5 is formed pulse

the fourth pulse of the sequence gc sequence of information units (Fig. 4). The signal from the output of trigger 19 for each pulse of the fourth sequence is stored on trigger 13 (Fig. 4i).

On the data bus 9, inverted to the synchronization signal, the signal from the second output of the trigger 10 is received. At the same time, the impulse from the output of the trigger 13 arrives at the installation input of the trigger and zeroes it. The trigger 14 maintains the zero state at the output until the first pulse of the fourth sequence after the end of the fallout pulse sets a high potential at the trigger output 14

nal is formed

sequence (Fig. 4i). The trigger 24 is zeroed by each pulse of the fifth sequence and is switched for each pulse of the fourth sequence (Fig. 4A).

The signal from the output of trigger 24 for each pulse of the fourth sequence is stored on trigger 2 (Fig. 4 (d). And at the inputs of element And 20 there are signals from the outputs of trigger 27 (fig, 4m) and element

When these signals coincide on the element And 5 pulsed

of the new characters (Fig. 4d), sent to the information bus 9, Inverse to the synchronization signal, the signal from the second output of the trigger 10 to the post

It goes to one of the inputs of the element And 22 At the second input of the element And 22 there are 1 pulses of the third sequence. When these signals are gonced by the output of the And 22 element, a pulse sequence of information symbol zeros is formed: (FIG, AC), Trigger 26 is pulsed with a sequence of zeroes of information symbols and switches on each difference from high level to low clock signal. The signal from the output of the trigger 26 (figure 4 (p) is fed to one of the inputs of the element And 23. At the second input of the element And 23 there are signals from the outputs (trigger 14 (Fig. 4i) and element And 8 (Fig. 4t). At the coincidence of these signals, the impulses of anti-transverse markers from the output of the element And 23 (fig, 4x) are fed to the bus 29 of the marker pulses.

Claims (2)

1. A method for detecting digital information signals manipulated in frequency and phase and reproduced from a magnetic carrier, according to the author. St. No. 1195376, characterized in that, in order to reduce the detection error due to the synchronization stability, the fourth pulse sequence pulses between the pulses of the fifth pulse sequence and each pulse following the specified number of pulses of the fourth pulse sequence are counted form the sixth impulse-O to the information input of the fourth sequence, after which the fourth pulse sequence is counted between the pulses of the sixth pulse sequence and for each of its pulses, 45 of the first element AND and the output to the next one after the specified number of pulses of the fourth pulse sequence, the seventh pulse sequence is formed, which pulses synchronize the generated pulse 50 of a given polarity of clock pulses, while simultaneously forming a sequence of anti-transverse markers by counting impulses the installation input of the fifth countable trigger, the connection (of the synchronous input with the output of the first counting trigger and P1) ghol - with the first output of the seventh element - And, connected by the second input to the output of the second element And, trog. The entrance to the exit is the second of the trigger and the exit to the additional bus; ten f5 25 35/4992 the fourth pulse sequence between impulses:, smly zeros of the numeric symbols at the moment of the formation of the first unit of information symbols after a given number of pulses of the fourth pulse sequence. 2. An apparatus for detecting frequency and phase handles. signals of digital information, reproduce, - izvimyhx with magnetic media, by author. St. No. 1195376, characterized in that, in order to reduce the detection error by increasing the synchronization stability, the fourth, fifth, sixth and seventh elements And, the third, fourth and fifth counting triggers and the fourth and fifth fifth triggers are introduced, the third AND element is connected by an output to the installation input of the first counting trigger through the fourth and fifth And elements connected in series, the last of which is connected by one of the inputs to the output of the fifth trigger connected by a synchronization input to the connected between the output of the decoder and the synchronization of the inputs of the fourth counting trigger, connected by the 1st output to the information input of the fifth trigger and the setup input - to the output of the fourth And element, the fourth trigger, connected by an output to one of the inputs of the fourth And element, and the third counting trigger, connected by an adjusting the input to the output of the third element And the input 20 trigger, the sixth element And is connected to the first input to the additional output of the first counting trigger, the second input to the output  the first element And the output - to  the first element And the output - to to the installation input of the fifth counting trigger, connect (synchronized input with the output of the first counting trigger and P1) ghol - with the first emit of the seventh element - And connected by the second input to the output of the second element And, trog. The entrance to the exit is the second of the trigger and the exit - to the additional bus; synchronization. gj -1 iJ And I I MI i I M I I I L JlJl JlJ1 riJirUlJTJin J 8TLL eight - . JLLJ. e JLLUJJJJULJJUUJ. Jail Well {I ... J- ™ i L1 "JlJlJlJ J JlJ lJlJnjnJlJlJnj .... J. ™ ... one JLLJ. gl 3 Jin Jl-Jin.J TJirLJTrTJ l JirL иLL and. I m I 1 I I II II J1-L I M M I M I I I I I I I I I I I M M I I I I I R I M W JTJlTTJOJinJinjiriJTJ 3 Kjljl l jnjnjnjHLjnjnjirijTrTJTjnjnjn M “I  jnjnjnjnjTjn rij-ijijnjnjaj P PI GT7i LII I I I I I I I I I 1: I Jl IL 1 I tLI