SU1059605A1 - Device for reproducing signals containing digital information - Google Patents

Abstract

A DEVICE FOR REPEATING DIGITAL INFORMATION SIGNALS, containing a series-connected magnetic head, amplifier, filter, first zero-impulse driver and sequentially connected impedance finder, first impulse former, extremum first element, the first element And, the first trigger and the second element And, interconnected by the impulse generator by the extremum, the first element And, the first trigger and the second element And, interconnected by the impulse generator by the extremum, the first element And, the first trigger and the second element And, connected between the interface, the impulse generator according to the extremum, the first element And, the first trigger and the second element And, connected between the interface, the impulse generator according to the extremum, the first element And, the first trigger and the second element And, connected between the interface, the impulse generator according to the extremum, the first element And, the first trigger and the second element And, connected between the interface, the impulse generator according to the extremum, the first element And, the first trigger and the second element And, connected by an interface above the target and the second input of the first trigger, the Schmidt trigger connected in series and the third element AND, the other input of which is connected to the output of the first pulse former on The second output of the Schmidt trigger is connected to another input of the first element AND, characterized by the fact that, with the aim of increasing the fidelity of reproduction, the second element of the impulse generator is connected to it in series, the fourth element is And, the second trigger, n And the third element, the third trigger and the sixth element And, between the output of the filter and the other input of the sixth element And - serially connected to the second pulse shaper at the extremum and the delay element, between the other output of the first t iggera and the second input of the fifth AND gate - sequentially soedinenn1e seventh AND gate and a fourth flip-flop, the second input of which is coupled to a second input of the second T {dagger and output of the first element & And, the output of the second pulse former, the second element I is connected by zero to the A (L second input of the third trigger, the output of the third element I is to the third input of the fifth element I, the output of the first pulse driver is zero to the other input of the seventh element And, another the input of the fourth element AND to the other output of the first trigger, and ate the output of the amplifier of the connection with the input. v. miso tel. O)

Description

The invention relates to instrumentation, in particular to equipment for reproducing digital information signals from a magnetic carrier. A known device for reproducing 1-digit information signals containing serially connected magnetic heads, an amplifier, a filter, as well as a connected zero-pulse driver and demodulator 1. In this device, when the amplitude of the reproduced signals or the pulse period changes, the synchronization pulse detection decreases (sync pulses) and signals information presented in the form of symbols. The closest to the proposed technical entity is a device for reproducing digital information signals, containing serially connected magnetic head, amplifier, zero pulse generator, detection unit and demodulator sync pulses, as well as a signal replacement unit associated with the pulse formaker input and output zero and with the output of the demodulator of the clock pulses, and a block of shaping the double frequency signals, connected to the outputs of the block of measuring signals 2. In a known device ve after amplification and filtering the reproduced signal is supplied to the demodulator clock, wherein after converting it in substitution block signal and the doubled frequency signal generating unit no changes due umenscheni reproduced signal amplitude. In the detecting unit, the number of pulses is calculated by zero, which are within the period of the following clock pulses, and by its results, units and zeros are allocated. Consequently, in this device, signals are selected based on length selection, However, with an increase in recording density due to the influence of intersymbol distortion, the reliability of demodulation is insufficient to ensure higher fidelity of reproduction. Namely, the known devices have a small correction ability of detection (the size of the detection window does not exceed ± 0.25 from the period of the sync pulses), which is a significant drawback with an increased recording density, and the selection of duration is the main factor in reducing the noise immunity of the entire device. whole The purpose of the invention is to increase the fidelity of the reproduction by expanding the detection area of the reproduced signals. To achieve this goal, a device for reproducing digital information signals, containing a serially connected magnetic head, a power amplifier, a filter, a first pulse shaper for zero and a serially connected sump, a first shaper of extremum, a first And element, a first trigger, and a second And element connected between the output of the rectifier and the second input of the first trigger of the Schmidt trigger connected in series and the third element I, the other input of which is connected to the output of the first form lm HMnjTibcoB at the extremum, and the second output of Schmidt trigger is connected to another input of the first element I, the second pulse generator connected to the output of the amplifier are connected in series, the fourth element And, the second trigger, the fifth element And, the third trigger and The sixth element, between the filter output and the other input of the sixth element And, are the series-connected second pulse driver for the extremum and the delay element, between the other output of the first trigger and the second input of the fifth element and I - in series with the union of the seventh AND gate and a fourth flip-flop, a second input coupled to a second input of the second flip-flop and The yields. the house of the first element is And, the output of the second pulse generator on zero is connected through the second element And to the second input of the third trigger, and the output of the third element And - to the third input of the fifth element And, the output of the first pulse generator on zero - to another input of the seventh element And, another the input of the fourth element And to the other output of the first trigger, and the output of the amplifier is connected to the input of the top of the bar. FIG. 1 shows a block diagram of the proposed device; in fig. 2 - time diaries: 1 programs that show his work. The device contains series-connected magnetic head 1, amplifier 2, filter 3, first shaper 4 pulses of zero and series-connected rectifier 5, first shaper 6 of extremum, first element And 7, first trigger 8, and second element And 9 connected between the output of the rectifier 5 and the second input of the trigger 8 are connected in series by Schmidt’s trigger 10 and the third element 11, the second input of which is connected to the first input of the first element 7, the second input of the latter is connected to the second output of the trigger 10 Schmidt. In addition to the device introduced

connected to the output of amplifier 2 are connected in series the second shaper 12 pulses of zero, the fourth element And 13, the second trigger 14, the fifth element And 15, the third trigger 16 and the sixth element And 17, between the output of the filter 3 and the second input of the sixth element And If - serially connected second expander 18 and element 19 for; 1 holders, between the second output of the first trigger 8 and the second input of the fifth element And 15 - the seventh element 20 and the fourth trigger 21, sequentially connected, the second input of which is connected to the second input the trigger 14 and is connected to the output of the first element I 7, the output of the amplifier 2 is connected to the input of the rectifier 5, the output of the second driver 12 pulses are zero connected via the second element 9 to the second input of the third trigger 16, the output of the third element II And to the third input p That element And 15, the output of the driver 4 pulses of zero - to the second input of the seventh element And 20, the second input of the fourth element And 13. - to the first output of the first trigger 8..

The device works as follows.

Reproduced by magnetic head 1 and amplified siphl (Fig. 2a) is converted by rectifier 5 and is formed by extreme values on the first form. rover 6 pulses (Fig. 26). The signal with usi likhel 2 is also generated by zero values on the second driver 12 pulses of zero (Fig. 2c). Cook and in the known device, in the proposed formation 5G (impulse of the incidence (Fig. 2 g) (on the trigger 10 PYIDT, the first and third elements of And 7 and 11 and the trigger 6), the fronts of which correspond to the TBjooT region of the reduced value of the reproduced signal. Signals of the decay are formed in two cases corresponding to the parasitic amplitude modulation and the pre-distortion of the recording signal when forming service differences. To distinguish them, the reproduced signal is filtered on filter 3 and the resulting signal is re-formed (Fig. 2e) on the second pulse shaper 18 according to the extremum y (Fig. 2e) and the first pulse shaper 4 according to zero (Fig. 2g). The received signals are processed on elements 9, 13, 15, 20 and triggers 14, 16, 21 The resetting of the second 14 and fourth 21 flip-flops is made by one of the pulses from the output of the first element I 7 (Fig. 2g), which coincides with the leading front of the slot, after the pulses on the fourth element I 13 (Fig. 2i). j

they arrive at the counting input of the second trigger 14. After the pulses are extracted at the seventh element AND 20 (Fig. 2k) O1SH arrive at the counting input of the fourth trigger 21. At the Sh) inputs the fourth and seventh elements And 13 and 20 an inverted pulse is applied fallout from the first trigger 8. The decoder uses the fifth element AND 15, the first, second and third inputs of which receive pulses from the output of the second 14, fourth 21 triggers and the third element And 11 (fig. 2l), respectively, from the output of the latter coincides with the back the pulse falling out.

When playing a fragment of a signal with. Specially introduced distinctive features in the structure of service drops, the number of pulses at the output of the fourth element I 13 (Fig. 2a) exceeds the number of pulses per

0 output of the seventh element And 20 (Fig. 2k). In this case, the second 14 and quarter 21 triggers are set to different states, which on the fifth element And 15 are compared with the signal at the output of the third element And 11

(figi 2l). At the output of the fifth element And 15 a pulse is formed (Fig. 2m).

In the presence of an impulse due to parasitic amplitude modulation, the second 14 and fourth 21 triggers are set to the same state (the same number of pulses at their inputs), and the output of the fifth element 15 does not generate a pulse. Thus, in the proposed device, at the output of the second element I 9 (FIG. 2) a pulse is formed which coincides outside the interval of the impulse of falling out with the closest impulse from the output of the second generator 12 of the pulses. At the output of the third trigger 16, inhibition pulses are generated (Fig. 2o). On the sixth element And 17, a comparison of the impulses from the output of the delay block 19 with the inhibit pulse is made and a sequence of pulses is formed (Fig 2p) corresponding to the initial information sequence 110100100011 at the output of the information source. The proposed device for reproducing digital information signals allows for an order of magnitude increase in the fidelity of reproducing information signals by detecting them on the basis of amplitude selection of signals recorded at a small time interval as ocean waves and used for detecting information signals, to improve the correcting ability of the demodulator 2 times due to the testing of temporal distortions up to ± 0.5T, where T is the period of the following binary code symbols, and also to increase the longitudinal density by 1.5-2 times Record-play information.

In addition, the proposed device allows to increase the correcting ability of the demodulator when playing signals

digital (registered with a large number of testing & ampli fi cation factors. In this case, the device allows increasing the longitudinal density of the fences while simultaneously reproducing the fidelity of reproduction by one order of magnitude.

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Claims (1)

DEVICE FOR PLAYING DIGITAL INFORMATION SIGNALS, comprising a series-connected magnetic head, amplifier, filter, a first pulse shaper to zero and a series-connected rectifier, a first pulse shaper to an extremum, a first element And, a first trigger and a second element And connected between the output of the rectifier and the second input of the first trigger connected in series Schmidt trigger and the third element And, the other input of which is connected to the output of the first pulse shaper extremum y, a second Schmidt trigger output connected to another input of the first element And, characterized in that, in order to increase fidelity of reproduction, a second pulse shaper connected to zero, a fourth element And, a second trigger, a fifth element And, a third trigger and a sixth element And, between the output of the filter and the other input of the sixth element And the series-connected second pulse generator at the extremum and the delay element, between the other output of the first trigger and the second input of the fifth element And the series-connected seventh element tent And and the fourth trigger, the second input of which is connected to the second input of the second trigger and the output of the first element And, the output of the second pulse shaper is connected through zero to the second input of the third trigger, the output of the third element And to the third input of the fifth element And , the output of the first pulse shaper is zero to another input of the seventh element And, the other input of the fourth element And to another output of the first trigger, and the output of the amplifier is connected to the input of the rectifier. »SU„, 1059605>