U.S. Philips Corporation

Franciscus A Kneepkens

Gerardus C Lokhoff

Johannes J Kalfs

Gustavus L Van Eijck

Pieter G Van Leeuwen

John F Sherry

In a transmission system a sequence of digital symbols including concatenated words, is transmitted by a transmitter (2) via a transmission medium (14) to a receiver (16). In order to reduce the transmission capacity no word synchronizing symbols are introduced in the sequence of digital symbols. In order to achieve word synchronization, a synchronization processor estimates the probability function of one single predetermined string as function of the position of the string in the sequence. The correct position of the words is derived from this probability function.

Transmission system having receiver for recovering words from sequence

For the clock extraction from n digital signals read from each of n tracks there are provided n phase-locked loops. In order to compensate for speed variations in the speed of transport of the record carrier there is provided an additional frequency control system. This system derives a control signal which is a measure of the speed variations, which control signal is applied to the voltage-controlled oscillators of all the phase-locked loops as a common control signal.

Apparatus for reproducing n digital signals from n adjacent tracks on a

Systems, apparatus and methods for recording or reproducing from a re-recordable record carrier digital signals, representing a digital audio signal, containing information which results in concealment of a portion of a replica of the digital audio signal during its reproduction to prohibit audio distortions resulting from a boundary between two digital signals, wherein one of those digital signal is newly-recorded over a previously-recorded other digital signal. The concealment information can also be included in auxiliary signals recorded on reproduced from the record carrier along with the digital signals. In a recording apparatus, a digital signal including audio information (i.e., data-reduced samples of sub-band signals derived from sub-band coding a digital audio signal, and bit allocation information and scale factor information relating to the quantized samples) is provided with, via a signal processing unit, mutilated information or a concealment code (possibly included in an auxiliary signal instead) indicating that a portion of the replica of the digital audio signal is to be concealed during its reproduction, and then, recorded on a re-recordable record carrier. The reproducing apparatus acts, via a concealment control signal and a concealment unit, as a result of the mutilated information or the concealment code included in a digital signal (or auxiliary signal) read or received from a re-recordable record carrier, to conceal a portion of the replica of the digital audio signal during its reproduction. In embodiments in which concealment codes are used, a detector is included in the reproducing apparatus to detect the concealment code.

System, apparatus and methods for recording and/or reproducing on and/or

The transmission system includes a transmitter for transmitting a sub-band-coded signal which is accommodated in a second digital signal (FIG. 2) having frames which incorporate allocation information, scale factor information and samples. In order to perform an additional signal processing operation on the received signal at the receiver end, the bit allocation information is already adapted for this purpose at the transmitter end. A signal processing control signal indicating which type of additional signal processing operation will have to be performed may be transmitted along with the information.

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Eindhoven, Netherlands

Franciscus A Kneepkens