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# EFMPIus: The coding format of the multimedia compact disc

## Abstract

We report on an alternative to Eight-to-Fourteen Modulation (EFM), called EFMPlus, which has been adopted as coding format of the MultiMedia Compact Disc proposal. The rate of the new code is 8/16, which means that a 6-7% higher information density can be obtained. EFMPlus is the spitting image of EFM (same minimum and maximum runlength, clock content etc). Computer simulations have shown that the low-frequency content of the new code is only slightly larger than its conventional EFM counterpart.
... In other words, the numbers of code states, r, ri, and r2 are Fibonacci numbers. By recursive elimination we can proof that [2] rNI(n -2) + rlNI(n -3) = NI(q)NI(n -2) + N1(q -I)NI(n - 3) = N1(n + q -1). ...
... For an RLL code, a large number of surplus codewords, i.e. larger than a power of two, is very beneficial for implementing a de-control as normally used in optical recording disc systems. The surplus words can be used as alternative channel representations, which are selected by the encoder to reduce the low-frequency components [3]. Case d=2 ...
Conference Paper
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We will report on a relationship between the size of certain runlength-limited (RLL) codes and encoder complexity expressed as the number of encoder states, where the number of encoder states equals a (generalized) Fibonacci number.
... The disc thickness was halved to 0.6 mm, which resulted in a higher storage capacity than possible with a disc of 1.2-mm thickness. Specifications of the obsolete 1.2 mm thick Multimedia CD disc can be found in Ref. 1. ...
... The number of data bits, Nb, that can be stored on the disc is given by (1) where A is the useful area of the disc surface, d is the diameter of the laser light spot on the disc, and 11 is the efficiency of the recording method. The (areal) information density is thus given by ...
Article
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The digital versatile disc (DVD) is a new optical recording medium with a storage capacity seven times higher than the conventional compact disc (CD). The major part of the capacity increase is achieved by the use of optics, shorter laser wavelength, and larger numerical aperture, which reduces the spot diameter by a factor of 1.65. The track formed by the recorded pits and lands, as well as the track pitch, can be reduced by the same factor. The storage capacity is further increased by a complete redesign of the logical format of the disc, including a more powerful error correction and recording code. The system requirements of the DVD and the related channel coding are outlined in this paper.
... Beginning in the late 1960's, rapidly evolving magnetic and optical recording technologies inspired a boom in research on coding for constrained systems (discrete noiseless channels with equal edge costs). Theoretical bounds on encoder and decoder properties were studied in [Ash87, Ash88, AM95,AMR95,Ash96,AKS96,AMR96], efficient construction algorithms were presented in [FW64,Fra68,Fra69,Fra70,TB70,ACH83,AFKM86], and codes for specific storage applications, some of which became industry standards, were described in [Fra72,Pat75,AHM82,INOO85,Imm95]. The extensive bibliographies in [MRS01,Imm04] provide additional references. ...
Preprint
Analytic combinatorics in several variables is a powerful tool for deriving the asymptotic behavior of combinatorial quantities by analyzing multivariate generating functions. We study information-theoretic questions about sequences in a discrete noiseless channel under cost and forbidden substring constraints. Our main contributions involve the relationship between the graph structure of the channel and the singularities of the bivariate generating function whose coefficients are the number of sequences satisfying the constraints. We combine these new results with methods from multivariate analytic combinatorics to solve questions in many application areas. For example, we determine the optimal coded synthesis rate for DNA data storage when the synthesis supersequence is any periodic string. This follows from a precise characterization of the number of subsequences of an arbitrary periodic strings. Along the way, we provide a new proof of the equivalence of the combinatorial and probabilistic definitions of the cost-constrained capacity, and we show that the cost-constrained channel capacity is determined by a cost-dependent singularity, generalizing Shannon's classical result for unconstrained capacity.
... The data formats include blue-ray Disk (BD) and high-definition DVD (HD DVD). Various kinds of coding schemes have been developed [4]- [6] for the ODD so that error detection is greatly improved for data reading out or writing in from/to the optical disk. However, if the wrong disk type is discriminated, all of the delicate coding Manuscript schemes are in vain, resulting in a fatal data reading or writing mistake. ...
Article
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A novel disk discrimination approach with two levels of classification is proposed. The optical pickup head is controlled to emit the digital versatile disk laser followed by the compact disk laser during the process of being pulled in from the neutral position toward the optical disk. Four features are measured and analyzed based on the reflected signals from the optical disk. Two levels of classifications are designed for the disk discrimination using these four features. A supervised learning approach based on the evolutionary ellipsoid classification algorithm is utilized to learn the classifiers and optimize the classifier parameterizations. Six different disk types have been successfully discriminated using the proposed approach.
... The data formats include blue-ray Disk (BD) and high-definition DVD (HD DVD). Various kinds of coding schemes have been developed [4] [6] for the ODD so that error detection is greatly improved for data reading out or writing in from/to the optical disk. However, if the wrong disk type is discriminated, all of the delicate coding Manuscript received July 7, 2014;revised January 3, 2015;accepted February 19, 2015 schemes are in vain, resulting in a fatal data reading or writing mistake. ...
Chapter
We consider the problem of timed channel coding: given two timed languages, can we transmit the information produced by the first, used as information source, as words of the second, used as communication channel? More precisely, we look at coding with bounded delay: having a uniform bound between the timed length of any word from the source and its encoding on the channel. Moreover, we consider approximated coding satisfying the following property: whenever the channel word is observed with precision $$\varepsilon '$$, then the original word can be recovered with precision $$\varepsilon$$.Our solution is based on the new notion of $$\varepsilon$$-bandwidth of a timed language, which characterises the quantity of information in its words, in bits per time unit, when these words are observed with precision $$\varepsilon$$. We present basic properties of $$\varepsilon$$-bandwidth of timed regular languages, and establish a necessary, and a sufficient simple condition for existence of bounded delay coding in terms of bandwidths of the source and the channel.
Article
We propose two modified versions of the classical gradient ascent method to compute the capacity of finite-state channels with Markovian inputs. For the case that the channel mutual information rate is strongly concave in a parameter taking values in a compact convex subset of some Euclidean space, our first algorithm proves to achieve polynomial accuracy in polynomial time and, moreover, for some special families of finite-state channels our algorithm can achieve exponential accuracy in polynomial time under some technical conditions. For the case that the channel mutual information rate may not be strongly concave, our second algorithm proves to be at least locally convergent.
Chapter
Baseband modulation codes are widely applied in such diverse fields as digital line transmission [21, 28, 18, 116], digital optical transmission [111, 16], and digital magnetic and optical storage [ 105, 100, 106]. They act to translate the source data sequence d n into a sequence a k that is transmitted across the channel (Fig. 4.1; see also Chapter 3). The principal goal is to enable the receiver to produce reliable decisions $${\hat d_n}$$ about d n . Code design should, therefore, account for the characteristics of both channel and receiver. (Because modulation coding is the only type of coding that we consider in this chapter, we shall usually say ‘coding’ where we mean ‘modulation coding’.)
Article
A new optical disc format with 650nm laser is introduced, which receives capacity of 5.4 to 6 GB for single layer and 9.8 to 11GB for double layers. The technologies developed in this new optical disc, including new data modulation code, error correction code, content protection and technologies related to triple layers disc, are also presented. For blue laser recording technologies, two kind of optical pickup head with 405nm laser were integrated. The resulting spots are observed. For terabyte storage, some advance technologies are developing. The spot overcoming diffraction limit and gap controlling are two major subjects for near field recording. Volumetric storage by multi-layer stacking could approach several hundreds gigabytes. The fluorescent material is adopted in multi-layer disc for reducing signal interference between layers.
Patent
Full-text available
A system for block encoding words of a digital signal achieves a maximum of error compaction and ensures reliability of a self-clocking decoder, while minimizing any DC in the encoded signal. Data words of m bits are translated into information blocks ofn1 bits (n1 >m) that satisfy a (d,k)-constraint in which at least d "0" bits, but no more than k "0" bits occur between consecutive "I" bits. The information blocks are concatenated by inserting separation blocks of n2 bits there between, selected so that the (d,k)-constraint is satisfied over the boundary between any two information words. For each information word, the separation block that will yield the lowest net digital sum value is selected. Then, the encoded signal is modulated as an NRZ-M signal in which a "1" becomes a transition and a "0" becomes an absence of a transition. A unique synchronizing block is inserted periodically. A decoder circuit, using the synchronizing blocks to control its timing, disregards the separation blocks, but detects the information blocks and translates them back into reconstituted data words of m bits. The foregoing technique can be used to advantage in recording digitized music on an optical disc.
Article
This paper describes a novel run-length limited code, termed 3PM. A group of three data bits is converted into six code bits which are represented by the presence or absence of signal transitions. At least two zeros are maintained between two consecutive ones, that is a minimum distance of three positions between transitions, resulting in great reduction of pulse crowding. The minimum distance is assured by a unique merging rule at the boundary of adjacent code words. This rule distinguishes the code from both fixed and variable length codes and results in very simple encoding and decoding algorithms. An actual 50% density increase has been accomplished in saturation recording by using the 3PM code in combination with other electronic techniques. The new code is used in a current ISS/Univac high density disk storage system, featuring 2500 bits/cm (6300 BPI) linear density, 10 Mbits/sec data rate, 338 MByte capacity and one bit in 10 billion raw error rate on conventional Mod-11 head/disk interface.
Article
Describes a new technique for constructing fixed-length (d,k) runlength-limited block codes. The new codes are very close to block-decodable codes, as decoding of the retrieved sequence can be accomplished by observing (part of) the received codeword plus a very small part (usually only a single bit) of the previous codeword. The basic idea of the new construction is to uniquely represent each source word by a (d,k) sequence with specific predefined properties, and to construct a bridge of β, 1&les;β&les;d, merging bits between every pair of adjacent words. An essential element of the new coding principle is look ahead. The merging bits are governed by the state of the encoder (the history), the present source word to be translated, and by the upcoming source word. The new constructions have the virtue that only one look-up table is required for encoding and decoding
The Art of Digital AudioA New Look-Ahead Code for Increas-ing Data Density
• J G V Watkinson
• Jacoby
J. Watkinson, The Art of Digital Audio, Focal Press, London, 1988. G.V. Jacoby, 'A New Look-Ahead Code for Increas-ing Data Density', IEEE Trans. Magn., vol.