JPH0341670A - Magnetic recording and reproducing device for digital signal - Google Patents

Abstract

PURPOSE:To protect an important part comprising a synchronizing signal and a mode data, etc., by recording this important part of an input digital signal in plural systems after performing a multivalued amplitude phase modulation and adding regenerative signals of the plural systems with their phases matched at the time of reproducing. CONSTITUTION:The important part such as the synchronizing signal and the mode data, etc., in the input digital signal is distributed as the same value to the plural systems, i.e. multivalued APSK modulators 4a and 4b. Then, they are modulated in multivalued amplitude phase respectively and recorded different positions on a magnetic recording medium 10, and at the time of reproducing the recorded signal, the regenerative signals of the plural systems are matched in phase and added up. By this method, the signal to noise ratio of the important part of the added regenerative signal is promoted, and the error rate of the important part for the synchronizing signal and the mode data, etc., can be lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a digital video tape recorder (DV).
The present invention relates to digital signal magnetic recording and reproducing devices such as TR).

2. Description of the Related Art In an apparatus for recording and reproducing digital signals on a magnetic recording medium, a synchronization signal is added to recorded data and recorded in order to serve as a reference for the data read position during reproduction. In the process of recording and reproducing, if an error occurs in the synchronization signal, the reference for the data read position is incorrect, resulting in a large amount of data errors. In conventional digital signal magnetic recording and reproducing devices, this error is corrected by adding an error correction code to the recorded signal and correcting it after reproduction (for example, a 1/2 inch digital VTR capable of recording for 12 hours, Yamamitsu Longevity Club, Akifumi Ide.

Akira Iketani, Tatsube Shigesato, Television Society Technical Report Vol. 1.
11, Na24. pp, 31-36. VR'87-33
(1987)).

Also, in the input signal, one part of the signal may be more important than other parts. For example, if the human signal is a signal obtained by performing band compression on audio and image data,
Depending on the band compression method, adaptive processing mode data, etc.
Data that is important to other parts is generated. The handling of such data is similar to the synchronization signal described above (for example, "Experiments on 1/2-inch consumer digital VTR" by Satoshi Itoi, Masami Hirata, and Ryuta Yochinaka).

Kenji Tagami, Katsuya Oshima, Kiyoshi Ohara, Minoru Ashibe, Television Society Technical Report V o 1.12. Fh56. p p, 2
s~30, VR' 8B-59 (198B)).

Problems to be Solved by the Invention However, in the configuration using the error correction code described above, since the error correction code is added to the entire recording signal, the synchronization signal,
If the correction capability for important parts such as mode data is made sufficient, the capability will far exceed the necessary capability for other recorded data, and the increase in redundancy due to the addition of error correction codes will be redundant. Become. One possible method is to add as many error correction codes as necessary to the entire recorded data, and add longer error correction codes only to important parts, but at the same time the redundancy of the important parts increases. The hardware required to separate the important parts becomes very complex. Furthermore, it was less effective against defects in the magnetic recording medium and burst groups caused by dust adhering to the surface of the medium.

In view of the above-mentioned problems, the present invention makes it possible to sufficiently protect important parts such as synchronization signals and mode data, while making the error correction code added to the recording signal shorter, making it possible to actually record it on tape. In addition to reducing the amount of data to be processed,
Compared to conventional technology, important parts are more strongly protected against bursts caused by defects in the magnetic recording medium and dust adhering to the surface of the medium. An object of the present invention is to provide a digital signal magnetic recording/reproducing device that prevents large amounts of data errors due to mode setting errors during decompression.

Means for Solving the Problems In order to solve the above problems, the present invention distributes an input digital signal into a plurality of digital signals having different contents and converts each into a multi-level digital signal, and at that time, encoding means for distributing only a portion of the input digital signal into a digital signal as digital signals having the same content; and a plurality of encoding means for generating a modulated signal by performing multi-value amplitude phase modulation on each of the plurality of systems of multi-value digital signals. a multi-value amplitude phase modulation means, and a magnetic recording/reproducing means for recording the modulation signals output from the plurality of multi-value amplitude phase modulation means in different positions of a magnetic recording medium and reproducing the recorded signals; a synthesizing means for adding and outputting a plurality of systems of reproduction signals from the magnetic recording and reproducing means in phase, and a plurality of demodulating signals for demodulating the reproduction signals of the plurality of systems and the output signal of the synthesis means into reproduction multilevel digital signals, respectively. The apparatus includes multilevel amplitude phase modulation demodulation means and decoding means for converting the plurality of systems of reproduced multilevel digital signals into reproduced digital signals.

Alternatively, the synthesizing means may include a phase shifting means for changing the phase of at least one of the manually inputted reproduction signals of the plurality of systems, and a phase shifting means for comparing the phase of the output signal of the phase shifting means between the systems. The apparatus includes phase difference detection means for controlling the phase shift means such that the phase difference decreases, and addition means for adding together a plurality of systems of reproduced signals output from the phase shift means.

Alternatively, the encoding means may include synchronization addition/encoding means for converting an input digital signal into multiple systems of multi-value digital signals and adding the same synchronization signal to each of the multiple systems of multi-value digital signals. , the decoding means detects a synchronization signal from a synthesized reproduced multi-level digital signal obtained by demodulating the output signal of the synthesis means, separates the synchronization signal from the plurality of systems of reproduced multi-level digital signals, and generates a reproduced digital signal; The device is equipped with a synchronization separation/decoding means for converting into .

Further, preferably, a bias circuit is provided to apply a bias signal to the modulation signals of the plurality of systems, and the output of the bias circuit may be recorded on a magnetic recording medium and reproduced.

According to the above-described configuration, the present invention distributes the important parts of the input digital signal, such as the synchronization signal and mode data, to multiple systems as the same value, and performs multi-level amplitude phase modulation on each of them to generate different signals on the magnetic recording medium. When recording to a position and reproducing the recorded signal, the reproduced signals of multiple systems are added with the same phase, so the signal-to-noise ratio of the important part of the added reproduced signal is compared with the reproduced signals of each system. becomes higher. Therefore, the error rate of important parts such as synchronization signals and mode data can be reduced, and a device can be constructed that prevents large amounts of data errors due to playback errors or synchronization disturbances of important input data, mode setting errors during band expansion, etc. .

It is possible to shorten the error correction code added to the recording signal while sufficiently protecting important parts such as synchronization signals and mode data, which reduces the amount of data actually recorded on tape and also protects important parts such as synchronization signals and mode data. Hardware can easily detect parts.

Furthermore, even if one system of signals among a plurality of systems of reproduction signals cannot be reproduced due to a defect in the magnetic recording medium or dust adhering to the surface of the medium, important parts can be demodulated from the reproduction signals of other systems.

Furthermore, by adding a bias signal to the modulation signal, the influence of nonlinear distortion can be alleviated, and recording and reproduction can be performed with a high error rate.

Embodiment Hereinafter, a digital signal recording/reproducing apparatus according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the main configuration of a digital magnetic recording and reproducing apparatus according to a first embodiment of the present invention. In this embodiment, analog signals such as television signals and audio signals are input to input terminal 1. is input. The input analog signal is converted to an analog/digital converter (hereinafter referred to as A/
The signal is converted into a digital signal by a D converter (or simply A/D) 2, and is input to a synchronization adding/encoding means 3.

The digital signal input to the synchronization adding/encoding means 3 is subjected to two systems of multi-value amplitude phase modulation (hereinafter, multi-value APSK).
(abbreviated as ) signals are converted into multi-level digital signals of two digits per system. At this time, synchronization signals of the same value are added to the two systems of multivalued digital signals. 2 output from the synchronization addition/encoding means 3
The multivalued digital signals of the system are multivalued (iAPsK
It is input to transformers 4a and 4b, and the carrier wave generation amount! 35
Each of the signals is multi-valued APSK modulated using the carrier wave inputted from the input signal and outputted.

For example, if the number of bits of the digital signal that is the output of the A/D converter 2 is 8, this digital signal is converted into a multi-value APSK
One of the methods is 16411 quadrature amplitude modulation (hereinafter referred to as 16411 quadrature amplitude modulation).
Consider the case of recording using QAM (abbreviated as QAM). At this time, the synchronization adding/encoding means 3 can be configured as shown in FIG. 2, for example.

In FIG. 2, from the A/D 2 to the synchronization addition/encoding means 3
The 8-bit digital signal inputted to the
01b respectively. On the other hand, the synchronization generation circuit 20
A 4-bit digital synchronization signal is generated at 2.

The synchronization signal is input to synchronization addition circuits 201a and 201b, and added to the two systems of 4-bit digital signals, respectively. A synchronization signal is added to the synchronization addition circuit 20
The 4-pin digital signal output from 1a is further
Each bit is divided into two systems, and the binary/four-value converter 203
a and 203b, respectively, and are converted into four-value digital signals. The four-value digital signal is a multi-value APS
It is manually input to the K modulator 4a. Similarly, regarding the 4-bit digital signal output from the synchronization addition circuit 201b,
Divided into 2 systems each with 2 bits, 2-value to 4-value converter 20
4a and 204b, and are converted into four-level digital signals and input to the multilevel APSK modulator 4b.

Returning to FIG. 1, the multi-value APSK signals output from the multi-value APSK modulators 4a and 4b are input to adders 6a and 6b, respectively, and are added to the bias signal output from the bias generation circuit 7.

The bias signal frequency 18 is the highest frequency fl of the recording signal band (where f8≧3・fH. This relationship is shown in FIG. 3. According to this relationship, f
The cross-modulation component of B-2.f is prevented from entering the recording signal band (here, f is an arbitrary frequency within the recording signal band).

The outputs of the adders 6a and 6b are input as recording signals to recording amplifiers 8a and 8b, respectively, and are input to recording amplifiers 9.
A and 9b record data at different positions on a magnetic recording medium IO (eg, a magnetic tape or a magnetic disk). Therefore, in the magnetic recording medium 10, as shown in FIG. 4, two different data are recorded in two tracks following a synchronization signal having the same content.

Next, on the reproduction side, two systems of recording signals are reproduced from the magnetic recording medium 10 via reproduction heads lla and 1lb (which can also be used in common with the recording head) and head ups 12a and 12b.

One of the two systems of reproduced signals is input to the phase shifter 13, and its phase is shifted. Output of phase shifter 13 and other l
The reproduced signal of the system is sent to the phase difference detection circuit 14 and the adder 15.
is input. The phase difference detection circuit 14 compares the phase of the output signal of the phase shifter 15 and the reproduced signal of one other system, and controls the phase shifter 13 so that the phase difference is minimized. Due to this operation, the output signal of the phase shifter 13 and the reproduction signal of one other system are added in phase by the adder 15.

The output of the adder 15 is input to a multilevel APSK demodulator 16c. The multi-level APSK demodulator 16c demodulates the composite reproduction signal, which is the output of the adder 15, into a multi-level digital signal.

By adding the two systems of playback signals in phase,
Assuming that noise generation is random, the synchronization signal amplitude will be twice that of the reproduced signal of only one system, the noise amplitude will be twice, and the signal-to-noise ratio (hereinafter abbreviated as S/N) of the synchronization signal will be
is 3 dB higher than the reproduced signal of only one system. The error rate of the synchronization signal is improved by this amount.

Furthermore, the two systems of reproduction signals that are the outputs of the head amplifiers 12a and 12b are multivalued A P S K'd, respectively.
The signals are also input to i-modulators 16a and 16b, and demodulated into multilevel digital signals. Multilevel APSK demodulators 16a, 16b
The regenerated multilevel dei sotal signal output from 16c and 16c is
The signal is input to the synchronization separation/decoding means 17 and converted into a digital signal.

In this embodiment, multilevel APSK modulators 4a and 4b,
The configuration of the multilevel APSKtl adjusters 16a, 16b, and 16c is not a direct object of the present invention, and is described in detail in the following document, so the details will be omitted.

(Literature) “Digital Microwave Communication” edited by Moriji Kuwahara, published by Planning Center, P, 133 (19B 4°5.25
First edition issued).

In this embodiment, the synchronization parsing/decoding means 17 can be configured as shown in FIG. 5, for example. In Figure 5, multivalued APS
The reproduced multi-level digital signal output from the K demodulator 16a is input to quaternary/binary converters 501a and 501b, and is also input to the clock regeneration circuit 502 as a reference signal for reproducing the clock. The reproduced 4-value digital signals inputted to the 4-value/2 (a converters 501a and 501b) are each converted into a reproduced (binary) digital signal of 2 bits each.Two systems of each 2 bits, a total of 4
The bit digital signal is input to a synchronization separation circuit 507.

Similar processing is performed on the reproduced multi-value digital signals that are the outputs of the multi-value APSK demodulators 16b and 16c.

The output of the multi-level APSK decoder 16b is inputted to the direct/binary converters 503a and 503b, converted to a digital signal, and input to the sync separation circuit 507.
The output of the SK demodulator 16c is input to 4-value/binary converters 505a and 505b, where it is converted into a digital signal and sent to a synchronization detection circuit 508 (two signals are output).

The synchronization detection circuit 508 detects a synchronization signal from the synthesized reproduction demodulated signal converted into the digital signal input from the 4(!/binary converters 505a and 505b) using the reproduction clock input from the clock reproduction circuit 506. and inputs the detection result to the synchronous separation circuit 507.The synchronous separation circuit 5
07 is 4 based on the detection result from the synchronization detection circuit 508.
Value/binary converters 501a, 501b, 503a and 50
Separate the synchronization signal from the output digital signal from 3b,
A digital/analog converter (hereinafter abbreviated as a D/A converter) converts only the reproduced data into an 8-pit digital signal.
Output to 18. When detecting the synchronization signal, detecting it from the synthesized reproduced demodulated signal makes it possible to improve synchronization signal detection errors.

Finally, returning to FIG. 1, the synchronous H/decoding means 17
The digital signal output from the D/A converter 1 is inputted to the D/A converter 1 and outputted from the output terminal 19 as a reproduced analog signal.

As described above, in the first embodiment, a synchronization signal with the same content is added to multiple systems of recorded data, each is subjected to multilevel amplitude phase modulation, and recorded at different positions on a magnetic recording medium.
When reproducing a recorded signal, multiple systems of reproducing signals are added together in phase, so the S/N of the synchronization signal portion of the added reproducing signal becomes higher than that of each system of reproducing signals. Therefore, the error rate of the synchronization signal can be reduced, and a device can be constructed that prevents a large amount of data errors due to synchronization disturbances. Furthermore, even if one system of signals among a plurality of systems of reproduction signals is not reproduced due to a defect in the magnetic recording medium or dust adhering to the surface of the medium, the synchronization signal can be demodulated from the reproduction signals of other systems.

In the first embodiment, the number of bits of the digital signal output from the A/D converter 2 is set to 8, and the case is considered in which this digital signal is recorded using 16QAM, which is one of the multilevel APSK methods. However, the number of bits of the digital signal and the number of values of the multi-fiAPsK system can be arbitrarily selected. Moreover, when distributing the modulated signal, although it is distributed into two systems, the number of systems can be set arbitrarily.

FIG. 6 shows a block diagram of a digital signal magnetic recording and reproducing apparatus according to a second embodiment of the present invention.

In FIG. 6, the difference from the embodiment in FIG. 1 is that instead of the synchronization addition/encoding means 3, the digital signal after A/D conversion is band-compressed and then converted into a multi-value digital signal. A band compression/encoding means 601 is provided for outputting the mode information signal to the APSK modulators 4a and 4b, and at that time outputs a mode information signal with the same content to both the multilevel APSK modulators 4a and 4b, and a synchronization separation/coding means 601 is provided. Instead of the decoding means 47, mode information is detected from the composite reproduced demodulated signal manually input from the multilevel APSK demodulator 16c, and the mode information is used to convert the reproduced multilevel digital signal from the multilevel APSK demodulators 16a and 16b. band expansion/decoding means 6 for expanding the band and outputting it to the D/A converter 18 as an 8-bit digital signal;
02 was provided.

Analog signals such as television signals and audio signals are input to the input terminal l. The input analog signal is converted into a digital signal by the A/D converter 2 and input to the band compression/encoding means 601. The digital signal manually input to the band compression/encoding means 601 is band compressed and converted into a multi-value digital signal of 2 digitals per 1 system corresponding to 2 systems of multi-value APSK signals.

For example, as in the first embodiment, consider a case where the number of bits of the digital signal output from the A/D converter 2 is 8, and this digital signal is recorded using 16QAM. At this time, the band pressure is 1 ft/encoding means 601, for example,
It can be configured as shown in the figure. In FIG. 7, an 8-bit digital signal input from the A/D 2 to band compression/encoding means 601 is input to band compression circuit 701. Regarding the band compression method in the band compression circuit 701,
For example, the method described in detail in the following documents mentioned as references in the prior art can be adopted. The details of the band compression method are not a direct objective of the present invention, so the details will be omitted.

(Literature) RL/2-inch consumer digital VTR experiment” Satoshi Itoi, Masami Hirata, Ryuta Yochinaka, Kenji Tagami, Katsuya Oshima,
Kiyoshi Ohara, Minoru Ashibe, Television Society Technical Report Vol. 1.
12. 56, pρ, 25-30, VR' 88-59
(1988) The band compression circuit 701 converts the band compressed image data into 4
Each bit is divided into two systems and output, and the mode information is output as one system of 4 bits. Band compression circuit 7
The two systems of 4-bit digital signals output from 01 are input to mode information multiplexing circuits 702a and 702b, respectively. The mode information is also input to the mode information multiplexing circuits 702a and 702b, and is multiplexed onto the two systems of 4-bit digital signals, respectively. The 4-bit digital signal multiplexed with mode information and output from the mode information multiplexing circuit 702a is further divided into two systems of 2 bits each, input to binary/quaternary converters 203a and 203b, respectively, and converted into a 4-level digital signal. converted. The four-value digital signal is input to a multi-value APSK modulator 4a. Similarly, the other 4-bit digital signal outputted from the mode information multiplexing circuit 702b is divided into two systems of 2 bits each and input to the binary/quaternary converters 204a and 204b, respectively, to convert the 4-bit digital signal into a 4-bit digital signal. and is input to the multilevel APSK modulator 4b.

Returning to FIG. 6, the two systems of multi-value digital signals output from the band compression/encoding means 601 are each converted into a multi-value AP
The carrier wave generation circuit 5 is manually operated by the SK modulators 4a and 4b.
Each of the signals is multi-valued APSK modulated using the carrier wave inputted from the input signal and outputted.

The multi-level APSK modulated signals are each sent to an adder 6a.
and 6b, and is added to the bias signal output from the bias generation circuit 7. The adders 6a and 6b
The outputs are input as recording signals to recording amplifiers 8a and 8b, respectively, and are recorded at different positions on a magnetic recording medium 10 (for example, a magnetic tape or a magnetic disk) by recording disks 9a and 9b.

Next, on the reproduction side, two systems of recording signals are reproduced from the magnetic recording medium IO via reproduction heads lla and 1lb (which can also be used in common with the recording head) and head amplifiers 12a and 12b.

One of the two systems of reproduced signals is input to the phase shifter 13, and its phase is shifted. The output of phase shifter 13 and the other 1
The reproduced signal of the system is sent to the phase difference detection circuit 14 and the adder 15.
is input. The phase difference detection circuit 14 compares the phase of the output signal of the phase shifter 15 and the reproduced signal of one other system, and controls the phase shifter 13 so that the phase difference is minimized. Due to this operation, the output signal of the phase shifter 13 and the reproduction signal of one other system are added in phase by the adder 15.

The output of the adder 11i15 is input to the multilevel APSK modulator 16c. The multilevel APSK modulator 16c includes an adder 15
The synthesized reproduced signal which is the output of is demodulated into a multilevel digital signal.

By adding the two systems of playback signals in phase,
Assuming that the noise generation is random, the S/N of the portion where the same value is recorded in the two systems will be 3 dB higher than the reproduced signal of only the one system.

The error rate of the signal in the portion where the same value is recorded in the two systems, that is, the mode information, is improved by this amount.

Furthermore, the two systems of reproduction signals that are the outputs of the head amplifiers 12a and 12b are sent to the multilevel APSK demodulator 1, respectively.
It is also input to 6a and 16b and demodulated into a multilevel digital signal. Multilevel APSK demodulators 16a, 16b and 16
The reproduced multilevel digital signal output from c is band-expanded/
The signal is input to decoding means 602 and converted into a digital signal.

In this embodiment, the band expansion/decoding means 602 can be configured as shown in FIG. 8, for example. In Fig. 8, multi-level AP
SK revenge? The regenerated multi-level digital signal output from the A converter 16a is input to the four-value/binary converters 501a and 501b, and is also input to the clock regeneration circuit 502 as a reference signal for regenerating the clock. The reproduced 4-value digital signals inputted to the 4-value/binary converters 501a and 501b are each converted into 2-bit reproduced (binary) digital signals. These two systems of 2 bits each, a total of 4 bits of digital signal, are input to a band expansion circuit 801.

Similar processing is performed on the reproduced multi-value digital signals that are the outputs of the multi-value APSK demodulators 16b and 16c.The output of the multi-value APSK demodulator 16b is 4-value/2 (a
The signals are inputted to converters 503a and 503b, converted into digital signals, and input into the band expansion circuit 801. The output of the multi-level APSK demodulator 16c is output to the 4-level/binary converter 505.
a and 505b, converted to a digital signal, and input to the mode selection circuit 802.

The mode selection circuit 802 has 4 (direct/211 converter 50
5a and 505b, mode information is obtained from the synthesized reproduced demodulated signal converted into a digital signal, and a mode switching signal for band expansion is output to the band expansion circuit 801. Based on the mode switching signal from the mode selection circuit 802, the band expansion circuit 801 selects the four-value/binary converter 5.
01a.

The band of the output digital signals from 501b, 503a and 503b is expanded and converted into an 8-bit digital signal.
Output to A converter 18. During the above band expansion, by obtaining mode information from the synthesized reproduced demodulated signal, it is possible to improve selection errors in the band expansion mode.

Finally, returning to FIG. 6, the band expansion/decoding means 60
The digital signal which is the output of 2 is input to the D/A converter 18 and outputted from the output terminal 19 as a reproduced analog signal.

As described above, in the second embodiment, when band compression is applied to an input signal, the compressed image data is distributed to multiple systems of recording data, and band compression mode selection information of the same content is distributed. Multiplex the recorded data of all systems. These multiple systems of recorded data are each subjected to multilevel amplitude phase modulation and recorded to different positions on the magnetic recording medium, and when reproducing the recorded signals, the multiple systems of reproduced signals are added together with the same phase. The S/N of the mode information portion of the added reproduced signal is higher than that of the reproduced signal of the system.

Therefore, the error rate of mode information can be lowered, and an apparatus can be constructed that prevents a large amount of data errors due to errors in mode selection for band expansion. Further, even if one of the plurality of systems of reproduction signals is not reproduced due to a defect in the magnetic recording medium or dust adhering to the surface of the medium, mode information can be demodulated from the reproduction signals of other systems.

Note that in the embodiments (first to second) of the present invention, when distributing the modulated signal, it is distributed into two systems, but the number of systems can be set arbitrarily.

Furthermore, in the embodiments (first to second) of the present invention,
Although the case using multilevel orthogonal amplitude modulation has been described, similar effects can be obtained with other modulation methods such as amplitude phase keying (APSK), phase keying (PSK), and frequency modulation (FSK).

Effects of the Invention As described above, according to the present invention, important parts of the input digital signal, such as synchronization signals and mode data, are distributed as the same value to a plurality of systems, and multi-level amplitude phase modulation is performed on each of them. When the recorded signal is recorded on another position on the magnetic recording medium and the recorded signal is reproduced, the reproduced signals of multiple systems are added together with the same phase, so compared to the reproduced signals of each system,
The signal-to-noise ratio of the important part of the added reproduced signal becomes high. Therefore, it is possible to reduce the error rate of important parts such as synchronization signals and mode data, and to prevent large amounts of data errors due to playback errors or disturbances in important input data, mode setting errors during band expansion, etc. can. It is possible to shorten the error correction code added to the recording signal while sufficiently protecting important parts such as synchronization signals and mode data, which reduces the amount of data actually recorded on tape and also protects important parts such as synchronization signals and mode data. Hardware can easily detect parts. Furthermore, even if one system of signals among a plurality of systems of reproduction signals cannot be reproduced due to a defect in the magnetic recording medium or dust adhering to the surface of the medium, important parts can be demodulated from the reproduction signals of other systems.

Furthermore, by adding a bias signal to the modulation signal, the influence of nonlinear distortion can be alleviated, and recording and reproduction can be performed with a high error rate.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a digital signal magnetic recording and reproducing apparatus according to the first embodiment of the present invention, FIG. 2 is a block diagram showing an example of the configuration of the synchronization addition/encoding means 3, and FIG. 4 is a conceptual diagram of a recording signal format on a magnetic recording medium. FIG. 5 is a block diagram showing an example of the configuration of a synchronous heating/decoding means. FIG. 6 is a conceptual diagram of a recording signal format on a magnetic recording medium. A block diagram of the digital signal magnetic recording and reproducing apparatus in the second embodiment, FIG. 7 is a block diagram showing one example of the band pressure lit/encoding means, and FIG.
FIG. 2 is a block diagram showing an example of a configuration of a decoding means. DESCRIPTION OF SYMBOLS 1... Input terminal, 2... A/D converter, 3... Synchronization addition/encoding means, 4 a, 4
b...Multi-level PASK modulator, 5...Carrier wave generation circuit, 6a, 6b...Adder, 7...
...Bias generation circuit, 8a, 8b... Recording amplifier, 9a, 9b... Recording head, 10.
...magnetic recording medium, lla, flb...
Reproduction head, 12a, 12b... Head amplifier, 13... Phase shifter, 14... Phase difference detection circuit, 15... Adder, 16 a , 16
b, 16 c...-multi [APSK modulator, 1
7... Synchronous separation/decoding means, 18...
・D/A converter, 19... Output terminal, 201a
. 201b...Synchronization addition circuit, 202...
・Synchronization generation circuit, 203a, 203b, 204a, 20
4b...Binary/quaternary converter, 501a, 501
b. 503a, 503b, 505a, 505b ---
4-value/2-value converter, 502, 504.506...
・Clock regeneration circuit, 507... Synchronization separation circuit, 508... Synchronization detection circuit, 601...
Bandwidth compression/encoding means, 602... Bandwidth expansion/decoding means, 701... Bandwidth compression circuit, 70
1a, 701b...Mode information multiplex circuit, 80
1...Band expansion circuit, 802...Mode selection circuit. Part 2 Surplus diagram P diagram Figure 8

Claims (6)

[Claims] (1) An input digital signal is divided into multiple systems of digital signals each having different contents and each is converted into a multivalued digital signal, and at this time, only a part of the input digital signal is divided into the multiple systems of digital signals so that they have the same content. a plurality of multi-value amplitude and phase modulation means for generating modulated signals by performing multi-value amplitude phase modulation on each of the plurality of multi-value digital signals; The modulated signals output from the amplitude and phase modulation means are respectively recorded at different positions on a magnetic recording medium, and the magnetic recording and reproducing means for reproducing the recorded signals are arranged to adjust the phase of the plurality of systems of reproduction signals from the magnetic recording and reproducing means. a combining means for adding and outputting the combined signal; a plurality of multilevel amplitude phase modulation demodulation means for demodulating the plurality of systems of reproduced signals and the output signal of the combining means into reproduced multilevel digital signals; A digital signal magnetic recording and reproducing apparatus comprising decoding means for converting a value digital signal into a reproduced digital signal. (2) As a synthesizing means, a phase shifting means changes the phase of at least one signal among the plurality of input reproduction signals, and the phase of the output signal of the phase shifting means is compared between the systems, and the phase difference is determined. 2. The digital signal magnetism according to claim 1, further comprising phase difference detection means for controlling said phase shift means so that said phase shift means is reduced, and addition means for adding together a plurality of systems of reproduction signals output from said phase shift means. Recording and playback device. (3) As the encoding means, a synchronization addition/encoding means converts the input digital signal into multiple systems of multi-value digital signals, and adds the same synchronization signal to each of the multiple systems of multi-value digital signals. , and as a decryption means,
Synchronization separation/decoding means detects a synchronization signal from a synthesized reproduced multi-value digital signal obtained by demodulating the output signal of the synthesis means, separates the synchronization signal from the reproduced multi-value digital signals of the plurality of systems, and converts the synchronization signal into a reproduced digital signal. Claims comprising (
1) The digital signal magnetic recording and reproducing device as described above. (4) The digital signal magnetic recording and reproducing apparatus according to claim 1, further comprising bias means for adding a bias signal to a plurality of systems of modulated signals, and inputting the modulated signal to which the bias signals have been added to the magnetic recording and reproducing means. (5) Claim (4) characterized in that the bias means adds a bias signal that minimizes nonlinear distortion of the reproduced signal from the magnetic recording medium to the output of the multilevel amplitude phase modulation means.
The digital signal magnetic recording and reproducing device described above. (6) The bias means is the highest frequency of the recording signal band.
Claim (1) characterized in that a bias signal having a frequency twice or more is added to the output of the multilevel amplitude phase modulation means (
4) The digital signal magnetic recording and reproducing device as described above.