JPS58104553A - Signal converting system - Google Patents

Abstract

PURPOSE:To prevent the decrease in frequencies in using the NRZI and to avoid the generation of crosstalk based on the decreased azimuth at high density recording, by excluding consecutive ''Os'' for converted signals. CONSTITUTION:In converting 2-bit (B1,B2) information into 3-bit (P1,P2P3), the formula of conversion is shown in equation I. The final bit of converted information before a 3-bit signal (27) is denoted as P3P. The converted signal is modulated with the NRZI and supplied to a rotary head device for recording. As a result, since no ''Os'' are consecutive in the converted signal, the decrease in frequencies can be prevented in using the NRZI and the generation of crosstalk based on the decreased azimuth loss can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION For example, two heads may have an angular spacing of 1110 degrees from each other.
When recording and reproducing information signals using the rotary head device provided with ..., the azimuth angle of each head is increased to prevent azimuth loss (to prevent azimuth loss, Efforts are being made to increase the density of kikama, excluding dobando.

In such a device, as the frequency of the recorded number adjustment number decreases, the azimuth loss decreases and tar stutter is more likely to occur.

For example, when recording a data signal obtained by converting an audio signal into PCM, a modulation called NRZI is performed. This inverts Shinshichi at @l'' in the data signal, and 10
” to prevent the signal from being inverted.

If K"O" continues in one data signal when using such NRZI, modulation No. 1 will not be inverted during that time, the frequency will decrease by 1°, and this If the signal is recorded at the above-mentioned high resolution, a tag stop will occur in consecutive 10'' sections, making it easy to make errors.

This invention proposes a conversion method for converting data signals so that such points K, @O'' are not consecutive.

In other words, in the present invention, 2-bit (B1.Bg) information is converted into 3-bit (P1ePl*PB) K, and the conversion formula at that time is P@ wm Pop @ Bl m Bs However, Safittas' p is The emotion converted into , f is the information to be converted next, and is designed to perform well in NRZI.

In this invention, there is no data signal! Break it down into bits. This disassembled 2 pits) (B1*Bfi)
As for K, there are four possible forms of these two bits, υ to a◆, as shown in item 111.

Ple'1e (Ple'1e)
Ps) signal. ζ Here, there are eight forms that these three bits can take, K(2) to (2), as shown in Section 2.

In these 8 types of signals, the combination of QυwHw (c) cannot be used because @O'' is consecutive. zu, 11tK@, the combination of trout cannot be continued, and the combination of - is 1& of the combination of (goods).
There is no carp to continue.

On the other hand, the combination of (2) and (2) is higher. , (2), even if either one of the fins is added, how do these become KIIl and 4'''?
There is no jin with consecutive O''s.

In ζ, convert pith υ to fin, aS to (goods), ring to (2), and axis to (2)K.

In this case, only when continuing from %(goods) to (goods)′″O″
are continuous.

In that case, C? The last bit Pl of the information transformed before j is detected, and this is the end of l1il'', which is the fifth l
Further convert KH to KcI3 as shown in llum, BK, and convert 1 (goods) to @.

On the other hand, if Psp is @0'', 1 means that the front of @ is also a punishment, as is clear from Figure 8. Therefore, (goods)
Considering the condition that the number is continuous, if 40 is followed by an even number of times as shown in the 4th Eλ, and the 7th 1lK (2) is stone, then the first fin is (as shown in the 411th BK). 2), convert the next fin to @, and repeat this pair to see through it.
This means that ``c2's punishment is converted to (2), and K(2) after the nin is that i blind.

Furthermore, as shown in the striped s diagram, if @ follows an odd number of times (8 members + 1) and then there is KcI4, the fin of 2m + 1st H is converted to - as shown in Figure 1118. , in this case, convert (goods) to (to).

Therefore, in this Jimei, first, when the input information is brocade and H, these are converted to ) and @.

Next, it is determined whether the input information is a word υ or a mouth, and it is also determined whether the information to be converted to the primary level is an aυ or a mouth. This determination of Itυ or B3 is performed by detecting that the first bit (Blf) of the information to be converted next is @O''.

When Iksf is @1'', aυ is converted to @.

Also, when Blf is @O'', it is further determined whether the previously converted information is (c).This determination (2) is based on the last ps of the previously converted information (Ps). Detect that it is @O' and [execute].

Then, when CPsp is 11''', convert 叡υ to @, and @
O”, convert all to @.

Furthermore, it is determined whether or not the input information is n, and P
Detect l. Then, when CPsp is wlm, Ql is converted to 6!4, and when @O'', the angle is converted to (2).

In this way, by converting 2-bit information into 3-bit information, it is possible to prevent K and l"OI" from being consecutive.

Furthermore, the above transformation is This can be done using the following conversion formula.

Therefore, in Fig. 6, the signal from input terminal (1) is 3
A bit shift register (2)K is supplied, and the signals B1 and B_sf from this shift register (2) are supplied to a conversion circuit (3)K which conforms to the above-mentioned conversion formula.

Furthermore, a 4-bit shift register (4) is provided, and the signals Pl, P, , Plf) from the conversion circuit (3) are supplied to the lower three bits, and the P signal obtained by the 4-bit IK is supplied.
A signal of sp is supplied to a conversion circuit (3)K. The signal from the shift register (4) is then taken out from the output terminal (5)K. Note that the shift registers (2) and (4) are shifted by 2 bits and 3 bits, respectively, during the output period.

Tonoyo 5KL, the converted signal is modulated with NRZI,
For example, recording is performed using a rotary head device RK.

Furthermore, when the signal converted by K as described above is to be inversely converted, the following procedure is performed.

First, if the NBZI@ sting information is fin or @, it is inversely converted to 6υ and a, respectively. Also, when the information is (2), it is reversely converted to 1.

Furthermore, it is determined whether the information extracted from the previous Kl is (c). This determination (c) is based on whether the first bit Plp and the third bit P3p of the previously extracted information are both ``OI''.
This is done by detecting that

Then, when Plp and Plp are both ``0'', (2) is converted to pith υ, and (to) is converted to 93. At other times (
C) is converted to asK, and (C) is converted to ti4.

In this way, the above-mentioned 3-bit information can be converted back to the original 8-bit information.

This inverse transformation is Blx-pm, -P1p+P1p*Pl@P3B@
wm PBp @ (Plp * Pg -4-p 1
p * PH) + pm, * pt or.

This can be done using the inverse conversion formula.

Therefore, in FIG. 7, the NRZI demodulated signal is supplied to input terminal (6) K. The signal from this input terminal (6) is supplied to a 6-bit shift register (71K), and the signals from this shift register (7) are P, %PI, P, and P, .

An inverse conversion circuit (
8) K is supplied. It's actually a 2-bit shift register (
9) is provided, and B1 s B from the inverse conversion circuit (8)
M signals are supplied. Then, the signal from the shift register (9) is outputted from the output terminal alKjl. Note that the shift registers (71 and (9) each have a period of one shift register k.
.

Shifted by 3 bits and 2 bits.

The inversely transformed signal is discarded at 5.

The signal is converted in this way, but according to the beginning, there is no continuous 00'' in the converted signal, so when NRZI is used, the KIIA vertical number does not decrease and high WI Horse mackerel ff if you are in a relationship
There is no possibility that JEls will become small and tarstalk will occur.

[Brief explanation of the drawing]

Figures 1 to s are diagrams for explaining the beginning, and Figures 6 and 711 are configuration diagrams of the amount of iron used for conversion and free capital, respectively. (1) is an input terminal, (2) and (4) are shift registers,
(3) is a conversion circuit, and (5) is an output terminal. Fig. 3 Fig. 4 Fig. 5 n vs. Fig. 6 Fig. 7

Claims (1)

[Claims] Converting 2 bits (Bs Bs) of information to 3 bits (Ps, Pm
*Ps) along with the conversion formula at that time, however,
In this signal conversion method, p of Naphitus is the previously converted information, f is the next converted information, and K is used to modulate with NRZI.