SU1089613A1 - Process for magnetic recording of digital information - Google Patents

Abstract

A METHOD FOR MAGNETIC RECORDING OF DIGITAL INFORMATION, presented in the form of a potential code, in which phase modulation is carried out on a 180 rectangular carrier with one of two bits of digital information, characterized in that, in order to increase the accuracy of reproduction of information, the front of the carrier is shifted position on 1/4 of the carrier period.

Description

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The invention relates to instrumentation, in particular, to the technique of recording digital information on a movable magnetic carrier. The known method of magnetic recording by forming the recording current according to the modulation result of each period of the carrier by one of two bits of digital information using a pulse sequence with a period having more than two different polarity pulses, the first of which is equal to half the period Cl3. The disadvantage of this method is that the intersymbol interference between the two is located-HbiMii in a series of one pn: for the responses does not allow for a high recording rate. The closest in technical essence to the present invention is a method of magnetic recording of digital information, presented in the form of a potential code, in which phase modulation is performed on 180 non-real square form with one of two bits of digital information, the front of the carrier coinciding with The start of bit position 23 is the disadvantage of this method is the need to take into account the temporal relationships in the reproduction signal, because the instability of the speed of movement of the carrier leads to a decrease in the reliability of reproduction no information. The purpose of the invention is to increase the accuracy of information reproduction. I The goal is achieved by the fact that, according to the method of magnetic recording of digital information, presented in the form of a potential code, which produces phase modulation on the rectangular-shaped ISO HecyLaeft with one of two bits of digital information, the carrier front is shifted from the beginning of the bit position by 1/4 of carrier period. FIG. 1 shows a block diagram of a device implementing the proposed method: in FIG. 2 shows diagrams illustrating the pagable method; The recording device comprises a delay element 1 connected in series, a phase multiplier 2, a recording amplifier 3, and a recording head 4. A carrier is fed to the input 5 of the delay element 1. The recorded code is received through the input terminal & to the second input of the phase modulator 2. Magnetic recording of digital information is carried out as follows. This information in the form of a potential code (Fig. 2, D) and clock pulses with a duty cycle of 2 (Fig. 2.6) arrive at the input terminals 6 and 5 of the recording device. Clock pulses are used as a carrier. They are delayed by 1/4 period by a 1 delay element. The delayed carrier (Fig. 2.8} is fed to the input of the phase modulator 2, where it is modulated in phase by a code from terminal 6 to the second input of the phase modulator. The result of the modulation is to form the recording current (Fig. 2, D) c recording amplifier 3, the input of which is connected to the output of the phase modulator 2, and the output to the recording head 4. Diagrams D and 6 {Fig. 2 S show the waveforms of the reproduced signals at different recording densities. Diagram D (Fig. 2} shows that during transitions in the code from 1 to O and vice versa, carrier shift leads to appearance of current recording an additional difference at the digital position boundary. This differential is corrective for two adjacent operating differences of one polarity. The reproduction signal (Fig. 2, A has two opposite polarity pulses for each information bit. This allows decoding information by logical devices without taking into account the temporal relationships in the reproduction signal. Such a waveform is observed at recording densities much higher than in method C (due to the presence of a correction period in the recording current). The plot (Fig. 2 shows the signal .1 obtained by reproducing information recorded with a density 1.5 times greater than in the previous case. It repeats in form the differentiated reproduction signal in the prototype. Therefore, it can be decoded by a device similar to used in the prototype, but without a differentiation unit. Thus, the use of the proposed method allows to increase the reliability of information reproduction and to simplify information reproduction devices due to excluded and differentiation unit.

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Claims (1)

METHOD FOR MAGNETIC RECORDING OF DIGITAL INFORMATION, presented in the form of a potential code, in which phase modulation of a 180 ° rectangular carrier by one of two bits of digital information is performed, characterized in that, in order to increase the fidelity of information reproduction, the carrier front is shifted from the beginning of the bit position by 1/4 carrier period. Figure 1>