SU1059608A1 - Method of multichannel reproducing of signals - Google Patents

Abstract

A MULTI-CHANNEL REPRODUCTION OF SIGNALS METHOD, which consists in forming the first pulse sequence in the cross channel, in the information channels — the second pulse sequence, demodulating the latter, digitizing the received signals, then storing, reading and converting them into analogue form, which distinguishes AND so that, in order to increase the number of recorded signals, the first sequence of pulses is divided into a sequence of marker signals and a third a sequence of pulses, from which, when the frequency is multiplied by n times, where n is an integer, forms a fourth sequence of pulses, while synchronizing time intervals are separated from the second sequences simultaneously with the demodulation, the frequency of the fourth sequence is divided 2.5 m n in m times where m is an integer, and form from them, respectively, the fifth sequence of pulses during synchronization with the signals of the markers and the sixth sequence of pulses during sig sync pulses, are allocated in the last series of (k + I) pulses, where k, I are integers, with the use of k pulses demodulated (L frequency pulse signals are converted to digital, and after storing, digital signals are read from signals the fifth sequence of pulses and their subsequent separation into rpynn i according to the signals of the markers. O1 with O) o 00

Description

The invention relates to magnetic recording, in particular, to reproduction methods using demodulation of frequency-pulse signals.

A device is known in which the reproduced signal is demodulated, and its low-frequency component is filtered. The result of the optical trap is digitized and represents a component due to the drift error of the recording-reproduction path, which is compensated for in the reproduced signal, for example, by subtracting 1 However, the known device, which performed public operations, does not have wide limits for compensating the temporal distortion of the information signal.

The closest to the proposed is oyusob according to one otorrhea reproduced sishaly rasfiltrovyvayuts, frequency-modulated signal is demodulated, the reference sigaal dolits discrete sampling chastotnoModulirovannogo converted signal into digital form and stored in buffer storage from which are read pulses of the reference frequency and converted to analog form 2

For the generally accepted ratio of the top frequency of the information signal to the carrier, equal to four, and the modulation depth of 40%, the implementation of these operators in the device allows to compensate for five times greater temporal distortion than in limescale devices. However, the number of simultaneously demodulated measuring signals cannot be straight (it will only extend one for a separate magnetic track.

The purpose of the invention is to increase the number of recorded signals.

This goal is achieved by the fact that, according to the method of reproducing signals, consisting in forming the first pulse sequence in the reference channel, in the information channels — second pulse sequences, demodulating the latter, converting the received signals into digital form, then storing them in analog form, the first sequence of pulses is divided into a sequence of marker signals and a third sequence of pulses, of which, when multiplied frequencies fi times where n is an integer form a fourth sequence of pulses, while synchronizing time intervals from the second sequences simultaneously with demodulation, after which they form sync pulses, divide the frequency of the fourth pulse sequence by 5 / 2m times and m times, where m is an integer,

and, respectively, the fifth pulse sequence during synchronization with the marker signals and the sixth pulse sequence during synchronization with the sync pulses are formed, the last demodulated (k + l) pulses are extracted, where k and I are whole numbers, using k pulses the demodulated pulse-frequency signals converted to digital, and the memorizer produces

reading out the digital signals by signals of the fifth pulse sequence and the subsequent separation of their group by the signals of the markers.

FIG. 1 shows a block diagram of a device that implements the proposed method; in fig. 2 - timing diagrams illustrating the proposed method.

One of the variants of the device that implements the proposed method of reproducing measuring signals comprises serially connected input bus 1, first pulse shaper 2, detection unit 3, frequency multiplier 4, second pulse shaper 5, first divider 6 and third pulse shaper 7 constituting together with switch 8 block 9 reference channel. The device also contains, connected in a certain way, the input alarm 10, the fourth pulse generator 11, the time interval detection unit 12, the fifth pulse driver 13, the pulse generator 14 series (k + l), the converter 15 analogue-. a digit, a memory block 16, a decoder 17, components together with a demodulator 18 frequency-pulse signals, a second divider 19 and a smart driver 20, converters 21 digital-analogue and 22 low-pass filters, as well as output buses 23 and 24 block 25 information channel. In block 9

the reference channel, the switch 8 with its inputs is in parallel connected to the outputs of the unit 3 detectable, and the setup inputs are comm. tator 8 and divider 6 are combined. In information channel block 25, a demodulator 18 of frequency-impulse signals is connected between the output of the fourth driver 11 of the pulses and the information input of the converter 15 analog-to-digit, the output of the fifth driver of the 13 pulses is connected to the installation input of the second divider 19 and the sixth pulse driver 20 is connected to the second input of the driver 14 series (k + l) pulses, the write input of the memory block 16 is connected to the output of the block 14, the outputs of the decoder 17 through digit-analogue and filter converters 21 The lower frequencies 22 are connected to output shields 23 and 24. Blocks 9 and 25 are interconnected as follows: the outputs of switch 3 of torus 8 are connected in parallel with the control inputs of the decoder 17, and the outputs of the second and third drivers 5 and 7 are respectively connected to the input of the second the divider 19 and the input information of the memory block 16 of the memory. The device works as follows. The reproduced signal of the reference channel, consisting of a mixture of synchronization pulses and measuring channel markers, is fed from the input bus 1 to the first driver 2 pulses, where it receives a conversion from a linear form to a pulse one (Fig. 2a). In detecting unit 3, a mixture of pulses is divided into synchronization pulses and markers of measuring channels (Fig. 26, c). The frequency of the reference channel synchronization pulses in the multiplier 4 frequencies and the second driver 5. The pulses increases by n times, and then by the first divider 6 block of the reference channel and the second divider 19 of the information channel block decreases by 5 / 2m and m times respectively (fnig.2g, th). In this case, the first divider 6 is reset to the initial state by markers of the Hbix channels with markers, and the second divider 19 is set up by pulses from the output of the fifth shaper of 13 pulses. At the outputs of the switch 8, control pulses are formed, each of which corresponds to the i-th measuring channel. At the output of the third pulse shaper 7, pulses of information are generated from the memory block 16. The information signal of the information channel, consisting of a mixture of frequency and 11 pulse-modulated signals of measuring channels separated by time intervals, is replayed from the input bus 10 to the fourth driver I, where it receives a conversion from a linear to a pulse form (Fig. 2g). The time interval detecting unit 12 selects time intervals from the pulse mixture, and the fifth pulse former 13 generates synchronizing pulses (Fig. 2e) at the end of the time intervals, which are synchronous but not in phase with the measuring channel markers due to magnetic distortions of the magnetic carrier. These synchronizing pulses, together with the pulse sequence received at the output of the second driver of the pulse generator 20, in the pulse shaper 14 series (k + l) of the pulses are transformed into two pulse sequences: one containing k pulses (FIG. 2z) corresponds to a fragment of a reproducible frequency-pulse -modulated signal, other, containing 1 pulse, corresponds to a fragment of the reproduced time interval. In further work, I pulses are not used. The demodulation result (Fig. 2i) from the demodulator 18 of the pulse-frequency modulated signals by the analog-to-digital converter 15 is translated into digital samples at the moments of arrival of each of the pulses and then stored in digital form in the memory block 16. Since the counting of digital samples from memory block 16 is carried out by pulses with a uniform period of time, from the output of the third driver 7 pulses, the information and control pulses are synchronous and in phase at the inputs of the decoder 17. The decoder 17 is a division of digital samples into groups, each of which belongs to one specific meter. to the channel. Obtaining the digital-to-analog conversion on the converter 21 and the low-pass filter 22, the information of each measuring channel goes to its output bus 23 (24) (Fig. 2k, l) with a delay, the value of which is determined by the capacity of the memory block 16. The proposed method, in comparison with the Prototype, allows an increase in the number of reproducible measuring channels. An experimental test showed that, in comparison with a known sample that implements one measuring channel with a frequency band of 0-20 kHz, two channels were reproduced with a frequency band of 0-8000 Hz with the following parameter values: n 100; m 40; k 32; I 8. The application of the proposed method in playback devices for measuring ousts allows reducing the number of expensive and labor-intensive to manufacture tape-testing mechanisms and multichannel blocks of magnetic heads. Practical use of the method is most appropriate in the reproduction apparatus of pulse-frequency-modulated signals from a magnetic medium obtained from an autonomous recording apparatus.

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Claims (1)

METHOD OF MULTI-CHANNEL PLAYBACK OF SIGNALS, which consists in the formation in the reference channel of the first sequence of pulses, in the information channels - the second sequence of pulses, demodulating the latter, converting the received signals into digital form, subsequent storing, reading and converting them into analog form, distinguishing it from I mean, in order to increase the number. of the recorded signals, the first sequence of pulses is divided into a sequence of marker signals and a third pulse sequence, from which, when the frequency is multiplied by η times, where η is an integer, a fourth sequence of pulses is formed, while synchronizing time pulses are extracted from the second sequences simultaneously with demodulation the intervals at the end of which the clock pulses form, divide the frequency of the fourth sequence into 2.5 m and m times ^ where m is an integer, and form the corresponding Actually, the fifth pulse sequence during synchronization with marker signals and the sixth pulse sequence during synchronization with sync pulses, are allocated in the last series of (k + I) pulses, where k, I are integers, using k pulses, the demodulated frequency-pulse signals are converted to digital, and after storing, the digital signals are read out according to the signals of the fifth pulse sequence and their subsequent division into a group according to marker signals. _a , SU. „L 059608