USRE44013EExpiredUtility
Digital sum variation computation method and system
Est. expiryOct 2, 2019(expired)· nominal 20-yr term from priority
G11B 2020/1461G11B 2020/1469G11B 2020/1457G11B 20/1426
63
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0
Cited by
16
References
12
Claims
Abstract
A digital sum variation (DSV) computation method and system is proposed, which is capable of determining the DSV value of a bit stream of channel-bit symbols to thereby find the optimal merge-bit symbol for insertion between each succeeding pair of the channel-bit symbols. This DSV computation method and system is characterized in the use of a Zero Digital Sum Variation (ZDSV) principle to determine the DSV. This DSV computation method and system can find the optimal merge-bit symbol for insertion between each succeeding pair of the channel-bit symbols in a more cost-effective manner with the need for a reduced amount of memory and utilizes a lookup table requiring a reduced amount of memory space for storage so that memory space can be reduced as compared to the prior art. This DSV computation method and system is therefore more advantageous to use than the prior art.
Claims
exact text as granted — not AI-modified1. A method for computing a zero digital sum variation (ZDSV) of a stream of channel-bit symbols, comprising the steps of:
(a) providing an initial value ZDSV n−1 , an initial value ODD(t 0 ˜efm n−1 ) and a initial bias value by a digital sum variation (DSV) computation system, wherein the initial value ZDSV n−1 is the zero digital sum variation of a previous start-to-channel-bit symbol efm n−1 , wherein the ODD(t 0 ˜efm n−1 ) indicates that the stream of the channel-bit symbols from a starting logic voltage state to the previous start-to-channel-bit symbol efm n−1 contains an odd-number or an even-number of 1s, the initial bias value is either 1 or −1;
(b) providing a current channel-bit symbol efm n by the DSV computation system, and obtaining a partial digital sum variation (PDSV) value PDSV(efm n ) and a ODD(efm n ) value in accordance with the current symbol efm n ;
(c) obtaining a plurality of partial digital sum variation (PDSV) values PDSV(m n i ) and ODD(m n i ) values in accordance with all possible merge-bit symbols m n i by the DSV computation system, wherein i=0, 1, . . . , x, the number of the possible merge-bit symbols is x+1;
(d) calculating ZDSV n i =ZDSV n−1 +ZDSV(m n i )+ZDSV(efm n ) i by the DSV computation system and calculating ODD(t 0 ˜efm n ) i =ODD(t 0 ˜efm n−1 )⊕ODD(m n i ).⊕ODD(efm n ) by the DSV computation system, wherein i=0, 1, . . . , x, in order to determine the ZDSV n of the zero digital sum variation of the current channel-bit symbol efm n , wherein ZDSV(m n i )=PDSV(m n i )*(−1) ODD(t0˜efmn−1) and ZDSV(efm n ) i =PDSV(efm n )*(−1) ODD(t0˜mni) , wherein ODD(t 0 ˜m n i )=ODD(t 0 ˜efm n−1 )⊕ODD(m n i ), wherein ⊕ represents the XOR logic operation,
the ZDSV n i is the zero digital sum variation of the channel-bit symbol efm n corresponding to the i-th merge-bit symbol of the possible merge-bit symbols,
the ZDSV(m n i ) means a zero digital sum variation of the i-th merge-bit symbol of the possible merge-bit symbols corresponding to the current channel-bit symbol efm n , the ZDSV(efm n ) i means a zero digital sum variation of the current channel-bit symbol efm n corresponding to the i-th merge-bit symbol of the possible merge-bit symbols;
(e) DSV n i =ZDSV n i +(initial bias value)*ODD(t 0 ˜efm n−1 ) i , wherein the DSV n i is a digital sum variation of the current channel-bit symbol efm n corresponding to the i-th merge-bit symbol of the possible merge-bit symbols;
(f) determining a final merge-bit symbol m n j in accordance with the absolute value of DSV n i and a run time limit by the DSV computation system, wherein jε{i}, wherein i=0, 1, . . . , x; and
(f) assigning the initial value ZDSV n−1 =ZDSV n j , the ODD(t 0 ˜efm n−1 )=ODD(t 0 ˜efm n ) j by the DSV computation system, and then jumping to step (b).
2. A method for use on a DVD system for computing a digital sum variation (DSV) of a data stream, comprising the steps of:
(a) providing a pre-determined zero digital sum variation initial value ZDSV n−1 , an initial value ODD(t 0 ˜efm n−1 ) and an initial bias value by a digital sum variation (DSV) computation system, the initial bias value is either 1 or −1;
(b) converting the data stream into a plurality of channel-bit symbol efm n i by the DSV computation system, wherein i=0, 1, 2, . . . , x;
(c) obtaining a partial digital sum variation (PDSV) value PDSV(efm n i ) and a ODD(efm n i ) value in accordance with the channel-bit symbol efm n i by the DSV computation system, wherein i=0, 1, 2, . . . , x;
(d) calculating ZDSV n i =ZDSV n−1 +ZDSV(efm n i ) and ODD(t 0 ˜efm n i )=ODD(t 0 ˜efm n−1 )⊕ODD(efm n i ) by the DSV computation system, wherein i=0, 1, . . . , x, in order to determine the ZDSV n i of the zero digital sum variation of the current channel-bit symbol efm n i , wherein ZDSV(efm n i )=PDSV(efm n i )*(−1) ODD(t0-efmn−1) , wherein
the ZDSV n i is the zero digital sum variation of the i-th channel-bit symbol efm n i ,
the ZDSV(efm n i ) means a zero digital sum variation of the i-th channel-bit symbol efm n i ;
(e) DSV n i =ZDSV n i +(the initial bias value)*ODD(t 0 ˜efm n i ), wherein the DSV n i is a digital sum variation of the i-th channel-bit symbol efm n i ;
(f) determining a final merge-bit symbol efm n j in accordance with the absolute value of the DSV n i and a coding rule by the DSV computation system, wherein jε{i}, wherein i=0, 1, . . . , x; and
(f) assigning by the DSV computation system the initial value ZDSV n−1 =ZDSV n j , the ODD(t 0 ˜efm n−1 )=ODD(t 0 ˜efm n j ), and then jumping to step (b).
3. A method for use on a DVD system for computing a digital sum variation (DSV) of a data stream, comprising the steps of:
(a) providing a pre-determined zero digital sum variation initial value ZDSV n−1 and an initial value ODD(t 0 ˜efm n−1 ) by a digital sum variation (DSV) computation system;
(b) converting the data stream into a plurality of channel-bit symbol efm n i by the DSV computation system, wherein i=0, 1, 2, . . . , x;
(c) obtaining a partial digital sum variation (PDSV) value PDSV(efm n i ) and a ODD(efm n i ) value in accordance with the corresponding channel-bit symbol efm n i by the DSV computation system, wherein i=0, 1, 2, . . . , x;
(d) calculating ZDSV n i =ZDSV n−1 +ZDSV(efm n i ) and ODD(t 0 ˜efm n i )=ODD(t 0 ˜efm n−1 )⊕ODD(efm n i ) by the DSV computation system, wherein i=0, 1, . . . , x, in order to determine the ZDSV n i of the zero digital sum variation of the current channel-bit symbol efm n i , wherein ZDSV(efm n i )=PDSV(efm n i )*(−1) ODD(to˜efmn−1) , wherein the ZDSV n i is the zero digital sum variation of the i-th channel-bit symbol efm n i , the ZDSV(efm n ) i means a zero digital sum variation of the i-th channel-bit symbol efm n i ,
(e) determining a final merge-bit symbol efm n j in accordance with the absolute value of the ZDSV(efm n i ) and a coding rule by the DSV computation system, wherein jε{i}, wherein i=0, 1, . . . , x; and
(f) assigning the initial value ZDSV n−j =ZDSV n j , the ODD(t 0 ˜efm n−1 )=ODD(t 0 ˜efm n j ) by the DSV computation system, and then jumping to step (b).
4. A method for generating a Zero digital sum variation (ZDSV) value of a Non-Return-to-Zero-and-Invert (NRZI) bit-stream, wherein the NRZI bit-stream comprises a first portion of bit-stream having a first ZDSV value, a merge-bit symbol, and a current channel-bit symbol, the method comprising:
calculating a segment ZDSV value of the merge-bit symbol by a digital sum variation (DSV) computation system; calculating a segment ZDSV value of the current channel-bit symbol by the DSV computation system; and summing the first ZDSV value, the segment ZDSV value of the merge-bit symbol and the segment ZDSV value of the current channel-bit symbol to generate the ZDSV value of the NRZI bit-stream by the DSV computation system.
5. The method as claimed in claim 4, wherein, in the merge-bit symbol, each series of consecutive zero bit are collected as a group, with 1 bit serving as the separator between each neighboring groups, and the step of calculating the segment ZDSV value of the merge-bit symbol comprises:
generating a partial ZDSV (PDSV) value of the merge-bit symbol by the DSV computation system; calculating a state of the merge-bit symbol by the DSV computation system; and multiplying the state of the merge-bit symbol by the PDSV value by the DSV computation system to obtain the segment ZDSV value of the merge-bit symbol.
6. The method as claimed in claim 5, wherein the step of generating the PDSV value of the merge-bit symbol by the DSV computation system is calculated according to the following algorithm:
PDSV
=
∑
x
=
1
n
GZ
x
·
(
-
1
)
x
;
wherein PDSV is the PDSV value, x is an index of the groups, GZx is a total number of zeros in a x-th group, and n is a total number of the group in the merge-bit symbol.
7. The method as claimed in claim 5, wherein the step of calculating a state of the merge-bit symbol by the DSV computation system is calculated according to the following algorithm:
State
=
(
-
1
)
ODD
;
wherein ODD indicates whether the merge-bit symbol comprises an odd-number or an even-number of 1's.
8. The method as claimed in claim 4, wherein, in the current channel-bit symbol, each series of consecutive zero bit are collected as a group, with 1 bit serving as the separator between each neighboring groups, and the step of calculating the segment ZDSV value of the current channel-bit symbol comprises:
generating a partial ZDSV (PDSV) value of the current channel-bit symbol by the DSV computation system; calculating a state of the current channel-bit symbol by the DSV computation system; and multiplying the state of the current channel-bit symbol by the PDSV value by the DSV computation system to obtain the segment ZDSV value of the current channel-bit symbol.
9. The method as claimed in claim 8, wherein the step of generating the PDSV value of the current channel-bit symbol by the DSV computation system is calculated according to the following algorithm:
PDSV
=
∑
x
=
1
n
GZ
x
·
(
-
1
)
x
;
wherein PDSV is the PDSV value, x is an index of the groups, GZx is a total number of zeros in a x-th group, and n is a total number of the group in the current channel-bit symbol.
10. The method as claimed in claim 8, wherein the step of calculating a state of the current channel-bit symbol by the DSV computation system is calculated according to the following algorithm:
State
=
(
-
1
)
ODD
;
wherein ODD indicates whether the current channel-bit symbol comprises an odd-number or an even-number of 1's.
11. The method as claimed in claim 8, wherein the step of generating the PDSV value of the current channel-bit symbol by the DSV computation system is calculated according to a lookup table.
12. The method as claimed in claim 4, wherein the method further comprises:
if a total number of 1s in the NRZI bit-stream is an even number, outputting the ZDSV value of the NRZI bit-stream by the DSV computation system to obtain the DSV value of the NRZI bit-stream; if the total number of 1s in the NRZI bit-stream is an odd number and a starting logic voltage state of the NRZI bit-stream is low, adding 1 to the ZDSV value of the NRZI bit-stream by the DSV computation system to obtain the DSV value of the NRZI bit-stream; and
if the total number of 1s in the NRZI bit-stream is an odd number and the starting logic voltage state of the NRZI bit-stream is high, subtracting 1 from the ZDSV value of the NRZI bit-stream by the DSV computation system to obtain the DSV value of the NRZI bit-stream.Cited by (0)
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