SU1269187A2 - Device for correcting limitation level when reproducing binary sequence from magnetic record medium - Google Patents

Abstract

The invention may find application in accurate magnetic recording and reproducing devices to compensate for inter-channel time distortion. The purpose of the invention is to improve the accuracy of control. The signal from the playback head 3 is fed respectively to the amplifier 6, the amplitude detector 7, the low-pass filter 8, from the output of which the smoothed voltage is fed to the input of the differential amplifier 5. The signal from the playback head 9 passes through the amplifier 10, the detector 11, the lower filter 12 frequencies and then to the second input of the differential amplifier 5. If there is a skew of the carrier 4 at the output of amplifiers 6, 10, signals of different amplitudes are input to the inputs of the differential amplifier 5, in the last p A signal is a signal whose magnitude is proportional to the amount of carrier skew, and the S sign is determined by the skew direction. The goal is achieved by simultaneously (reproducing a periodic signal with two heads of 3 and 9 reproduction. 1 or. Ke 05 Co oo Go

Description

one

The invention relates to the field of magnetic recording, namely, devices for correcting the level of limitation when playing a binary sequence from a magnetic recording medium and is an improvement of the device according to the author. St. No. 1117690.

The purpose of the invention is to reduce the error in reproducing a binary sequence from a magnetic recording medium.

The drawing shows a device for correcting the level of limitation in reproducing a binary sequence from a magnetic recording medium.

The device contains an input information bus 1 connected to the amplifier 2, driver-limiter 3, first delay element 4 connected to the first input of the pulse extraction unit 5 from the limitation interval, amplitude filter 6, driver of the limitation level 7, second delay element 8, third element 9 delay connected by the output to the first input of the element OR 10, the strobe key 11 connected by the output to the output P1nne 12, the driver of 13 clock pulses connected by the input to the bus 14 of synchronization, the fourth element 15 delays and block 16 for determining the number of differences in signal and interference parameters. The output of the amplifier 2 is connected to the first input of the limiter 3, to the input of the first delay element 4 and to the first input of the amplitude filter 6, the second input of the restriction level 7 connected to the nerve output. The amplitude filter 6 is connected to the first output of the first input of the limiting level generator 7, the second output --- to the second input of the extraction unit 5 from the limiting internally and to the input of the third delay element 9, and the third output to the third input of the selection 5 pulse from the limiting interval and the input of the third delay element 9. The output of the element OR 10 is connected to the first input of the gate key 11. The output of the generator 13 clock pulses is connected to the second input of the generator 7 of the level limiter connected by the third input to the output of the generator limiter 3. The fourth element 15 of the delay is connected by the input to the output of the generator 13 of clock pulses, and the output - to the fourth input of the pulse extraction unit 5 from the limitation interval and to the first input of the block 16 for determining the values of the dissociation; signal and noise parameters. The second and third inputs of the block 16 for determining the values of the error of the signal parameters and the numbers are connected to the first and second outputs of the node 5: imi имиu: 1s from I1gga: n5a; 1a restrictions.

The device also contains the first and second adders 17 and 18, the fifth and sixth delay elements 19 and 20, the comparator unit 21 and the control signal generator 22, connected by an input to the additional output of the pulse extraction unit 5 from the limit interval. The output of the driver 22 of the control signal series is connected to the control inputs of the first and second adders 17 and 18 and the comparison unit 21 and with the first auxiliary input of the block 16 for determining the error values of signal and interference parameters. The fifth and sixth delay elements 19 and 20 are connected between the second and third outputs of the limit level generator 7 and the second and third additional inputs of the block 16 for determining the error values of signal and interference parameters. The outputs of the first and second adders 17 and 18 are connected to the inputs

0 of the comparator unit 21 connected by the output to the second input of the element OR 10. The unit 16 for determining the error values of signal parameters and interference is connected by the fourth and fifth additional inputs to the outputs of the second and third elements 8 and 9

5 is delayed and is provided with control input 23. A gate key 11 is connected by a second input to the output of a fourth delay element 15.

The device also contains the first and second multipliers 24 and 25 voltages through which the inputs of the first and second adders 17 and 18, respectively, are connected to the outputs of the unit 16 for determining the deviation values of signal and interference parameters performed with the additional outputs 26 the error parameters of the signal parameters and the determinant of 27 weighting coefficients of the interference parameters. The determinant 26 of the weighting coefficients of the error parameters of the signals and

0 determiner 27 mismatch weight coefficients of the interference parameters are connected to the inputs of the first and second multipliers 24 and 25 voltages respectively, connected by other inputs to the output of the driver of a series of control signals, and connected by the first inputs to the additional outputs of the block 16 for determining the values of the error of signal parameters and interference. The second inputs of the determinant 26 weighting coefficients of the error parameters of the signals and the determinant

0 27 mismatch weighting coefficients of the interference parameters are connected to the control input 23 of the unit 16 for determining the error values of the signal parameters and interference.

5 The limitation level correction when playing a binary sequence from a magnetic recording medium is as follows.

The result of playing a binary sequence from a magnetic recording medium, coming through the input information bus 1, passes through amplifier 2 to driver-limiter 3, to the first delay element 4 and to amplitude filter 6. Driver-limiter 3 also receives a threshold signal from driver limiter 7 . Signals are received from the amplitude filter 6, the amplitude of which is greater than the upper threshold level or lower than the lower threshold level. This excludes from the formation of the level of limitation in the shaper 7 of the limiting level, those pulses of signals and interference, the erroneous difference of which in terms of one amplitude parameter is most likely. Single pulses corresponding to pulses whose amplitude is greater than the upper threshold level pass through the third delay element 9, the OR 10 element and the gate key 11 to the output bus 12. The pulses whose amplitude is in the interval between the lower and upper threshold levels are separated in the node 5, the extraction of pulses from the limitation interval and is supplied to the block 16 for determining the magnitudes of the error of signal parameters and interference.

At the same time, the pulse extraction unit 5 from the limiting interval acts on the driver 22 of the control signal series. Zero pulses corresponding to pulses whose amplitude is less than the lower threshold level and single pulses from the limiting level generator 7 pass through the sixth and fifth delay elements 20 and 19 per unit 16 for determining the error values of signal and interference parameters. From the last mismatch value, the averaged amplitude, duration, and phase of the signal are fed to the determinant 26 of the weighting coefficients of the signal parameters, and the mismatch of the averaged amplitude, duration and interference phase to the determinant of the 27 weighting coefficients of the interference parameter parameters. The latter, in accordance with the control signal from the control input 23 of the block 16 for determining the values of the error signal and interference parameters

develop weights of these parameters and act on the first and second multipliers 24 and 25 voltages. The weighted mismatch values of the signal parameters and the weighted mismatch parameter values of the interference parameters are received, respectively, to the first and second adders 17 and 18, from which the total mismatch codes are sent to the comparison unit 21. The latter forms a single impulse only if the sum of the weighted values of the error parameters of the signal parameters is less than the sum of the weighted values of the error parameter mismatches. This single impulse passes through the element OR 10 and the strobe key 11 to the output HIHHV 12.

Claims (1)

Invention Formula 0 Device for correcting the level of limitation when playing a binary sequence from a magnetic recording medium according to the author. St. .No 1117690, characterized in that, in order to reduce the reproduction error of the binary sequence, the first and second voltage multipliers are introduced into it, through which the inputs of the first and second adders respectively are connected to the outputs of the unit for determining the deviation values of the signal and interference parameters performed with 0 additional outputs, the determinant of the mass error factors of the signal parameters and the determinant of the mass error factors of the interference parameters, the determinant of the mass error coefficients of signal parameters and the determinant of the mass error coefficient of the interference parameters connected to the additional outputs of the unit for determining the error values of the signal parameters and interference are connected the second inputs with up equals the input of the block for determining the values of matching parameters and interference signals and outputs connected to inputs of the first and second voltage peremnozhnteley connected other 5 inputs with the output of the driver of a series of control signals.