Abstract: A method comprises determining the distance between a first transceiver unit and a second transceiver unit, wherein the first transceiver unit is mounted on a vehicle and the second transceiver unit is mounted on a trailer connected to the vehicle. The method also includes determining at least one parameter relating to the trailer, taking into account the distance between the first transceiver unit and the second transceiver unit.

Abstract: A method is provided for receiving and restoring data from an optical recording medium exhibiting strong asymmetry in the regenerated RF signal. The method provides digital partial response asymmetry compensation of a digital RF signal. The asymmetry of the digital RF signal is detected through the measurement of the envelopes of a short T pulse (xT pulse) and a long T pulse (yT pulse), where the T is the bit clock of the recovered bit stream. Through the evaluation of the xT upper and lower envelopes and the asymmetry factor, upper and lower thresholds are determined. Only the asymmetric parts of the digital RF signal are selected and compensated.

Abstract: A bit clock recovery apparatus for digital storage readout employing sync frames, where an oversampled readout signal is stored in memory, sync patterns are located in the signal using DSP means, distances of consecutive sync pattern locations are calculated, and bit clock is recovered from these distances and the knowledge about the data framing structure.

Abstract: A method and apparatus for error correction of an encoded data stream. A demodulated data stream is saved in an input buffer. A first correction process is performed on-the-fly in the input buffer. The data is transferred to an external SDRAM after correction. A data frame is copied from the external SDRAM to an embedded SRAM. A multipass correction is started in the embedded SRAM. The corrected data frame is copied back from the embedded SRAM to the external SDRAM.

Abstract: The invention is related to a method and an arrangement for recovering a binary DC-free code from a frequency-modulated signal, without any analog signal demodulation of the frequency-modulated signal. The invention relates more particularly to an ATIP bi-phase channel bit and timing recovery in a deteriorated wobble channel as e.g. required for high speed recording on optical storage media. The arrangement comprises a digital phase lock loop and a phase detector uses a phase trellis and a maximum likelihood detection is applied to the phase trellis for providing a bi-phase channel bit signal and a bi-phase clock signal, which is in time with the sampling point for the bi-phase channel bit signal for recovering said binary code. The invention is also applicable for further data transmission systems based on frequency modulation as e.g. modem or wireless data communication systems.

Abstract: The present invention relates to a device for reading from and/or writing to optical recording media (1) having an optical scanner (2) for scanning the recording medium (1) by means of a light beam (3) and for generating scanning signals (HF) from the reflected beam (3), a data slicer (5) for converting a scanning signal (HF) output by the optical scanner (2) into a binary signal (HF?), an averaging unit (6) for forming an average value (M) from the scanning signal (HF, HF?) as input signal of the data slicer (5), and a control unit (14) for changing a parameter (T, OF) of the averaging unit (6). The object of the present invention is to propose a device of this type and also a suitable method therefor in which the average value (M) can be adapted to disturbances during the scanning of the recording medium.

Abstract: The invention relates to a Reed-Solomon decoder and to a method of soft decision decoding of Reed-Solomon codes, wherein a syndrome polynomial, an erasure polynomial, and a modified syndrome polynomial are computed on-the-fly in parallel by iteratively updating coefficients of these polynomials.

Abstract: A method for determining the address of a frame inside a data sector of an optical recording medium (17), the sector comprising a plurality of frames, each frame being preceded by a synchronization code, and an apparatus (10) for reading from and/or writing to optical recording media (17) using such method. A method for determining the address of a frame inside a data sector of an optical recording medium (17) that is robust against streaming loss is proposed. The method comprises the steps of: keeping a history of previously detected synchronization codes; appending (2) the detected synchronization code to the history; comparing (3) a pattern of the last synchronisation codes with a plurality of valid patterns of synchronization codes; delivering (4) a valid frame address if the pattern corresponds to a valid pattern, the frame address corresponding to the valid pattern, and delivering (7) an error frame address if the pattern does not correspond to a valid pattern.

Abstract: A method and arrangement for using Synchronous Dynamic Random Access Memory (SDRAM) as storage for correction and track buffering in front end ICs of optical recording or reproduction devices. Data to be stored or read is organized in appropriate bursts for accelerating the SDRAM (SDR) traffic. The SDRAM is built around two banks of memory, and are accessed using a pipelined address logic, thereby accelerating access speeds.

Abstract: The present invention relates to a full-digital implementation of a differential phase detector and to an interpolator for such a differential phase detector. According to the invention a differential phase detector for generating a tracking error signal from the digitized signals (A, B, C, D) of four photodetectors, having a multiplexer for time multiplexing the digitized signals (A, B, C, D), includes a demultiplexer/interpolator for synchronizing the samples from the time multiplexed digitized signals (A, B, C, D). The demultiplexer/interpolator favorably receives a four signal time multiplex and generates four channels at half the speed of the time multiplex.

Abstract: The present invention relates to a method for receiving and restoring data from an optical recording medium exhibiting strong asymmetry in the regenerated RF signal. According to the invention a method for digital partial response asymmetry compensation of a digital RF signal comprises the steps of: —detecting the asymmetry ? of the digital RF signal through the measurement of the envelopes of a short T pulse (xT pluse) and a long T pulse (yT pulse), T being the bit clock of the recovered bit stream, —determining upper and lower thresholds through the evaluation of the XT upper and lower envelopes and the asymmetry factor ?, and—selecting and compensating only the asymmetric parts of the digital RF signal.

Abstract: A bit clock recovery apparatus for digital storage readout employing sync frames, where an oversampled readout signal is stored in memory, sync patterns are located in the signal using DSP means, distances of consecutive sync pattern locations are calculated, and bit clock is recovered from these distances and the knowledge about the data framing structure.

Abstract: An apparatus for reading from or writing to optical recording media, having a photodetector and a phase detector for detecting a phase difference between output signals of the photodetector. An object of the present invention is to propose an apparatus in which a phase signal which is as correct as possible is generated. A further object of the invention is to specify a method of which a correct track error signal is determined using a phase detection method. According to the invention, the apparatus has an edge sequence detector for detecting the sequence of edges of the output signals, and a signal blocking unit for blocking the output signal of the phase detector. In particular, the output signal of the phase detector is blocked when an impermissible sequence of zero crossings of phase detected signals.

Abstract: The present invention relates to soft-decision decoding of Reed-Solomon product codes. According to the invention, a method for error correction of an encoded data stream comprises the steps of: saving the demodulated data stream in an input buffer; performing a first correction process on-the-fly in the input buffer; transferring the data to an external SDRAM after correction; copying a data frame from the external SDRAM to an embedded SRAM; starting a multipass correction in the embedded SRAM; and copying the corrected data frame back from the embedded SRAM to the external SDRAM.

Abstract: Method for tracking in an apparatus for reading from and/or writing to an optical recording medium, and corresponding apparatus for reading from and/or writing to an optical recording medium. In order, in an apparatus for reading from and/or writing to an optical recording medium (18), to enable exact counting of the tracks of the optical recording medium (18) crossed by an optical scanning unit (16), it is proposed to derive a signal corresponding to the TZC signal (Tracking ZeroCross) and also a signal corresponding to the MZC signal (Mirror Zero Cross) from the output signal or the output signals (OUT1, OUT2) of a phase comparator (1) provided for tracking in accordance with the so-called differential phase detection method.

Abstract: The invention relates to a Reed-Solomon decoder and to a method of soft-decision decoding of Reed-Solomon codes, wherein a syndrome polynomial, an erasure polynomial and a modified syndrome polynomial are computed the-flyin parallel by iteratively updating coefficients of these polynomials.

Abstract: Disclosed is an apparatus for detecting a signal received from a channel signal and for transforming this signal into a binary code sequence via a signal processing apparatus, which can perform a maximum likelihood detection of the reproduced data from an optical disk with reduced complexity. Accordingly, a method to detect a signal (EBS) received from a channel signal (HF), comprises the steps of digitizing the signal received from the channel, equalizing the digitized signal (Ak), generating branch metrics (b_mp, b_pm) from the equalized signal (Bk), determining the minimum (b_ml) of the generated branch metrics (b_mp, b_pm), determining a merge (m−, m+, m0) from the minimum (b_ml), and generating a bitstream signal from the succession of merges (m−, m+, m0).

Abstract: The invention relates to a method for cross interleave Reed-Solomon code correction comprising the steps of:

Abstract: DVDs have currently the highest storage density among the optical discs of practical use. Due to the high storage density the reproduced signal is deteriorated by noise caused by inter-symbol interference, crosstalk, focus error, or mastering errors. A conventional threshold bit detector generates a high bit error rate in case of low SNR. For accurate reproduction of digital data from a DVD under low SNR conditions, a specific Viterbi detector is used which performs maximum likelihood sequence estimation.

Abstract: A method for determining the address of a frame inside a data sector of an optical recording medium (17), the sector comprising a plurality of frames, each frame being preceded by a synchronization code, and an apparatus (10) for reading from and/or writing to optical recording media (17) using such method.