Abstract: Presently known d=1 codes have long trains consisting of consecutive 2T runs and an overall high frequency of occurrence of the shortest 2T runs that reduce the performance of the bit detector By using a code with an MTR constraint of 2 an improvement in the bit detection is achieved. A code constructed in a systematic way that provides an MTR constraint of 2 is presented. A variation of such a code is disclosed where one sub-code is used, where coding states are divided into coding classes and where code words are divided into code word types. Then, for a given sub-code, an code word of type t can be concatenated with an code word of the next sub-code if said subsequent code word of said next sub-code belongs to one of coding states of the coding class with index Tmax+1 t.

Abstract: A body parameter sensing arrangement comprising clothing (10) and a plurality of sensors (12, 20) for sensing body signals, located at mutually movable relative positions in the clothing (10). Processing circuit (26) coupled to the plurality of sensors (12, 20), is configured to identify selected ones of the sensors (12, 20) that carry valid body signals. The identification by clustering the sensors (12, 20) according to similarity between signals from the sensors (12, 20). A cluster of sensors (12, 20) is determined with a maximal count of sensors (12, 20) within a minimal cluster diameter A cluster diameter defined by a measure of similarity or distance between signals form the sensors is used.

Abstract: The present invention relates to a method and a corresponding device for embedding a secondary information signal in a channel data stream of encoded primary information signal. In order to make it more difficult for unauthorized persons or devices to retrieve the location of storage of the secondary information signal or its content itself a device is proposed according to the present invention comprising: an encoder (1) for encoding said primary information signal into a channel data stream, a control unit (3) for controlling the DC content of said channel data stream, a secondary information signal embedding unit (2) for embedding said secondary information signal in said channel data stream by using freedoms in the DC control, and an adaptation unit (4) for adapting the DC control by making non-optimal, arbitrary or random choices of the DC control at a number of locations of said channel data stream.

Abstract: This invention relates to a method of converting a user bitstream into a coded bitstream by means of a runlengh limited (d, k) channel code where the channel code has a constraint of d=1. In order to ensure an improvement in bit detection performance an additional RMTR constraint of r=2 is imposed limiting to two the maximum number of minimum runs allowed by the d=1 constraint. An additional advantage of such a code is a limitation of the back-tracking depth of a Viterbi bit-detector Based on two different k constraints the construction of such d=1 and r=2 codes is disclosed.

Abstract: This ID proposes synchronization patterns for RLL codes with a (repeated) minimum transition run (RMTR) constraint, where the synchronization pattern comprises a synchronization pattern-body that contains a characteristic bit-pattern that represents a violation of the RMTR constraint. Using a violation of the RMTR constraint allows for short synchronization patterns.

Abstract: On existing DVD and CD players a control loop is required for the adaptation and timing recovery. For Two-Dimensional Optical Storage such a control loop has drawbacks because PRML detection in the form of a stripe-wise Viterbi detector is used. Such a detector introduces an increasing detection delay when going from the outer rows towards the center of the broad spiral. A feedback loop is arranged to determining an error signal from a first area of the data block where the first area is that area where the error signal can be determined within the shortest period of time. This reduces the duration of the detection step and thus increases the stability of the control loop.

Abstract: Presently known codes have long trains consisting of 2T runs that reduce the performance of the bit detector. By using a code with an RMTR constraint of 2 an improvement in the bit detection is achieved. A code constructed is a systematic way that provides an RMTR constraint of 2 is presented. Several variations of such a code are disclosed where one or more sub-codes are used, where coding states are divided into coding classes and where code words are divided into code word types. Then, for a given sub-code, a code word type t can be concatenated with a code word of the next sub-code if the subsequent code word of the next sub-code belongs to one of coding states of the coding class with index Tmax+1?t.

Abstract: The present invention relates to a symbol detection apparatus for detecting the symbol values of a one-dimensional channel data stream recorded along one-dimensional contiguous tracks on a record carrier, wherein the symbols of adjacent tracks have a varying phase relation.

Abstract: Devices and methods, record carrier and signal for embedding, extracting, carrying and representing secondary signal such as a copy protection signal embedded in a primary signal such as a blu ray disc signal modulated by a 17PP RMTR runlength limited modulation code. Each frame comprises a frame sync patterns followed by DC control blocks each including a DC control bit. Two modulation tables are used. Each bit of the secondary signal is represented by a relationship between the polarity of the frame sync signal and the values of the DC control bits in a fashion which complies with the constraints of the modulation code and the DC control algorithm.

Abstract: The present invention relates to an encoding apparatus and a corresponding method for two-dimensionally encoding user data of a user data stream into channel data of a channel data stream along a two-dimensional channel strip of at least two bit rows one-dimensionally evolving along a first direction and being aligned with each other along a second direction, said two directions constituting a two-dimensional lattice of bit positions. According to the invention the apparatus comprises a modulation code encoder for modulation code encoding said user data into said channel data according to a two-dimensional modulation code being adapted to prevent predetermined worst case patterns of channel data in said channel data stream. The worst-case patterns are typical for high-density two-dimensional optical storage channels.

Abstract: The invention relates to a method for generating a primary binary signal having a predetermined spectral shape in a predetermined frequency range, in particular having a notch in the power spectrum in a predetermined frequency range. In order to avoid crosstalk between a primary binary signal and a secondary binary signal it is proposed according to the invention that data-words are modulated into channel-words forming the channel bitstream of the primary binary signal and that the modulation of the data-words is chosen such that the predetermined spectral shape of the channel bitstream of the primary binary signal is achieved by using an evaluation criterion based on a spectral weight function the shape of which is tailored to the spectral extent of the channel bitstream of a secondary binary signal.

Abstract: A writing scheme for writing an information to an optical recording medium by forming mark areas, e.g. pit areas, corresponding to a predetermined state of said information on a recording surface of said optical recording medium. The writing scheme is adapted to modulate the shape of said mark areas in a predetermined manner so as to obtain incomplete mark areas which do not fully cover the size which is allocated to the channel bit to be written. The incomplete mark areas may be obtained by modulating their shape in any manner suitable to reduce the reflection surface and/or to increase diffraction. Additionally, a multi-level modulation or a binary modulation may be achieved by controlling the shape or number of the incomplete mark areas, respectively, in accordance with the level of a multi-level coded information.

Abstract: A signal includes a runlength limited (RLL) encoded binary d,k channel bitstream, parameter d defining a minimum number and k defining a maximum number of zeroes between any two ones of the bitstream, or vice versa. The signal further includes a number of sections of respectively N successive RLL channel bits, called RLL rows, each RLL row representing a row parity-check code-word, in which a row-based parity-check constraint for the RLL row has been realized. K sections of respectively N successive channel bits, called column parity-check rows, are located at predetermined positions of a group of M RLL rows. The column parity-check rows include column parity-check enabling channel words, each realizing a column-based parity-check constraint for all corresponding segments of at least the M RLL rows of the group that correspond to a specific column parity-check enabling channel word, thereby constituting a column parity-check codeword.

Abstract: An optical scanning device for scanning an optical record carrier comprising an information layer. Crosstalk cancellation is provided using a phase modulating element (40, 140) for generating a non-rotationally-symmetric phase profile in a subsidiary radiation beam. The phase profile varies with an azimuthal angle measured about the optical axis of the beam portion, the phase profile varying such that successively different phases are introduced in at least five locations which are each at successive azimuthal angles (?1, ?2, ?N) and each at a given radial distance from the optical axis, wherein the phase profile is such that the phases introduced, when taken in modulo 2? form, successively cycle through 0 to 2? at least twice, whereby the subsidiary beam spot is provided with an intensity distribution on the information layer which overlaps that of the side-lobe of the main beam spot.

Abstract: The invention relates to a method of storing a number of data bits of a secondary channel (30) in the frame of a main channel (20) and to a method of decoding a stream of bits relating to a secondary channel (30) embedded in the frames of a main channel (20) into a stream of data bits (62). In order to enable a certain synchronization and to guarantee a fixed amount of storage capacity in the secondary channel as well as to be able to correct deletions or insertions of bits in the secondary channel it is proposed according to the invention to form a secondary frame (11) having a fixed number of frame bits, to fill a fixed part of the secondary frame (11) with data bits (113), an end-bit (114) set to a first bit-value and, if necessary, with filling bits (115) set to a second bit-value, to encode the secondary frame (11) producing encoded data bits (113) and parity bits (112), which are finally embedded in the frame of the main channel (20).

Abstract: The invention relates to a method of converting a stream of databits of a binary information signal into a stream of databits of a constrained binary channel signal. This stream of databits of the binary information signal is divided into n-bit information words. These information words are converted into m1-bit channel words, in accordance with a channel code C1, or m2-bit channel words, in accordance with a channel code C2, where m1, m2 and n are integers for which it holds that m2>m1?n. The m2-bit channel word is chosen from of at least two m2-bit channel words, at least two of which have opposite parities, the concatenated m1-bit channel words and the m2-bit channel words complying with a runlength constraint of the binary channel signal.

Abstract: In a method of multi-dimensionally encoding a user data stream of user words into a channel data stream of channel words evolving in a one-dimensional direction of infinite extent, a user word is encoded into an NRZ channel word by selecting a NRZ channel word from a code table depending on the user word and the current state of an underlying finite-state-machine. A NRZ channel word comprises a sequence of NRZ channel symbols of NRZ channel bits having a one-dimensional interpretation along said one-dimensional direction and wherein states of an underlying finite-state-machine describing the characteristics of the multi-dimensional code are defined by NRZI channel bits of the previous channel work and by NRZ channel symbols of the current channel word. The NRZ channel symbols are transcoded into NRZI channel symbols by a one-dimensional 1T-precoding operation including an intergration modulo 2, said 1T-precoding operation being carried out along said one-dimensional direction of infinite extent.

Abstract: A Viterbi bit detection method for detecting the bit values of bits of a channel data stream stored on a record carrier along an N-dimensional channel tube, N being at least two, of at least two bit rows one-dimensionally evolving along a first direction and being aligned with each other along at least a second of N?1 other directions, the first direction together with the N?1 other directions constituting an N-dimensional lattice of bit positions, includes application of a row-based one-dimensional Viterbi bit detection method independent for each of the bit rows of said channel tube.

Abstract: An information system according to the invention comprises a record carrier and a playback apparatus. The record carrier has information marks along a track thereof and exhibits first variations caused by existence and nonexistence of the information marks along the track. The first variations represent an information signal recorded on said record carrier. The record carrier further exhibits second variations caused by variations associated with the information marks. The phase of the second variations is coupled to the phase of the first variations.

Abstract: A method and device for adding or extracting a secondary information signal to/from a runlength-limited code sequence, includes detecting a polarity of a runlength at a first predetermined position of the runlength-limited code sequence and setting a parameter reflecting the degree of freedom that is present in the runlength-limited channel code, e.g., the selection of a merging bit pattern in the CD-standard, on the basis of the detected polarity so as to obtain a predetermined polarity of a runlength at a subsequent second predetermined position of the runlength-limited code sequence. The predetermined polarity then corresponds to a binary value of the secondary information. Thus, a side-channel with a small capacity is provided, which is positioned very close to the physical channel such that the secondary information is hard to be detected from the EFM bit stream. Therefore, the side-channel can be used as a hidden channel for copy protection purposes.