Patents Represented by Attorney, Agent or Law Firm Eric P. Herrmann
  • Patent number: 6445423
    Abstract: A receiver for processing a VSB modulated signal containing terrestrial broadcast high definition television information includes an input analog-to-digital converter (19) for producing a digital datastream. A symbol timing recovery and segment sync recovery network (24; FIG. 3, 4) develops a properly timed sampling clock for the digital converter (19). The symbol timing recovery network (310) responds to an output from the segment sync recovery network (328), which in turn responds to an equalized signal from an adaptive channel equalizer (34). A controlled oscillator (336) generates the sampling clock for the digital converter. A control network (340, 344, 348; FIG. 3) shifts the frequency range of the oscillator to maintain desired linear operation to enhance symbol timing acquisition.
    Type: Grant
    Filed: July 9, 1999
    Date of Patent: September 3, 2002
    Assignee: Thomson Licensing S.A.
    Inventors: Aaron Reel Bouillet, David Glen White
  • Patent number: 6266380
    Abstract: A receiver for processing a VSB modulated signal containing terrestrial broadcast high definition television information and a pilot component includes an input analog-to-digital converter (19) for producing a datastream which is oversampled at twice the received symbol rate, and a digital demodulator (22; FIG. 3) with a data reduction network (330, 332) in a phase control loop. A segment sync detector (24; FIGS. 4, 5) uses an abbreviated correlation reference pattern to recover a twice symbol rate sampling clock for the digital converter (19). A DC offset associated with the pilot component is removed (26; FIG. 6) from the demodulated signal before it is applied to an NTSC interference detection network (30; FIG. 7). The interference detection network includes a comb filter network (710, 718) responsive to a twice symbol rate sampled data datastream, and exhibits a sample delay dimensioned to avoid aliasing in the combed frequency spectrum (FIG.
    Type: Grant
    Filed: August 26, 1998
    Date of Patent: July 24, 2001
    Assignee: Thomson Licensing, S.A.
    Inventor: Tian Jun Wang
  • Patent number: 6233295
    Abstract: A receiver for processing a VSB modulated signal containing terrestrial broadcast high definition television information and a pilot component includes an input analog-to-digital converter (19) for producing a datastream which is oversampled at twice the received symbol rate, and a digital demodulator (22; FIG. 3) with a data reduction network (330, 332) in a phase control loop. A segment sync detector (24; FIGS. 4, 5) uses an abbreviated correlation reference pattern to recover a twice symbol rate sampling clock for the digital converter (19). A DC offset associated with the pilot component is removed (26; FIG. 6) from the demodulated signal before it is applied to an NTSC interference detection network (30; FIG. 7). The interference detection network includes a comb filter network (710, 718) responsive to a twice symbol rate sampled data datastream, and exhibits a sample delay dimensioned to avoid aliasing in the combed frequency spectrum (FIG.
    Type: Grant
    Filed: August 26, 1998
    Date of Patent: May 15, 2001
    Assignee: Thomson Licensing S.A.
    Inventor: Tian Jun Wang
  • Patent number: 6230141
    Abstract: Dolby AC-3 and MPEG-2 audio permit the transmission of audio signals with more than two independent audio channels. If a reproduction device has only a two-channel audio decoder (DEC1) then an external multi-channel audio decoder (DEC2) can be used for multi-channel sound reproduction. If the audio reproduction at the same time accompanies video reproduction, then a synchronization method is required in order to achieve lip synchronism between picture and sound. According to the invention, for the synchronization of a first decoder (DEC1), which merely has two-channel compatibility, with a second decoder, which has multi-channel compatibility, a counting variable is allocated a value (F) which is produced from system parameters such as the data coding method used, the transmission speed and/or the data rate. The data are received by the first decoder and output by the latter to the second decoder, the counting variable being decremented or incremented respectively for a specific volume of data.
    Type: Grant
    Filed: December 4, 1998
    Date of Patent: May 8, 2001
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventors: Johannes Böhm, Ernst F. Schröder
  • Patent number: 6229464
    Abstract: A digital VSB modulator includes a modulator to which an ongoing sampled data stream of 1-sample-per-symbol successive PCM symbol signal samples are applied as a modulating signal. A sampled carrier stream, occurring at the rate of the signal samples, is applied as a carrier input to the modulator. The carrier stream is composed of, for example, a repeated 4-sample-sequence of 1, −1, −1, 1 sample values. The output of the modulator is applied to a bifurcated multiplexed N-tap root Nyquist FIR filter, which produces a VSB bifurcated complex output signal having a DC-centered real (±R) sampled data output stream of 1-sample-per-symbol sample values and a DC-centered imaginary (±I) sampled data output stream of 1-sample-per-symbol sample values.
    Type: Grant
    Filed: August 24, 1999
    Date of Patent: May 8, 2001
    Assignee: Thomson Licensing S.A.
    Inventor: David Lowell McNeely
  • Patent number: 6229925
    Abstract: The invention relates to a device for pre-processing video images intended to be coded in the MPEG 2 format. The MPEG 2 standard provides that, mode which exploits the spatial redundancy of the images. The images thus coded then define a succession of groups of images, a group of images being referred to as a GOP. The pre-processing device according to the invention comprises an image memory and an analysis circuit. The image memory makes it possible to store the various images contained in the forecast GOP of rank ok and ax of the first few images contained in the GOP of rank ok+l, ax being an integer greater than or equal to 1. The analysis circuit is linked to the image memory and makes it possible to perform measurements on the images contained therein. The knowledge about the images of the GOP of rank and about the first images of the forecast GOP of rank k+1 which is ascertained following the above mentioned measurements is then used for coding the GOP of rank k.
    Type: Grant
    Filed: May 19, 1998
    Date of Patent: May 8, 2001
    Assignee: Thomas Broadcast Systems
    Inventors: Patrice Alexandre, Jean-Christophe Morizur, Claude Perron
  • Patent number: 6181385
    Abstract: A method is proposed for processing transitional regions in a picture signal. The picture signal comprises a sequence of digital pixel values. A number of adjacent pixel values, which contain a processing pixel value, are combined to form a processing block. A corrected pixel value is calculated for the processing pixel value. The maximum and minimum pixel values are first determined in the processing block to define the transitional region. The transitional region is then split into a number of sections on the basis of the magnitude of pixel value. Finally, a determination is made as to the section in which the processing pixel value is located. The processing pixel value is allocated a corresponding correction value in order to increase, to reduce or to leave unchanged the processing pixel value, in accordance with a predetermined transfer function.
    Type: Grant
    Filed: May 18, 1998
    Date of Patent: January 30, 2001
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventor: Carlos Correa
  • Patent number: 6160785
    Abstract: In a further development of the CD, the so-called DVD, a data format was chosen which is upwards compatible with the CD. As a result, existing audio CDs can also be played on a DVD player. If complete error correction is not possible during the reproduction of a CD by an audio CD player, then simple measures for error concealment are additionally taken, but they are not always adequate. However, for cost reasons more complicated methods are not used in an audio CD player, since they would require a more powerful processor and a larger memory. However, a DVD player has this more complex hardware in any event, in order to enable the outstanding video quality that is intended.
    Type: Grant
    Filed: March 4, 1998
    Date of Patent: December 12, 2000
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventor: Ingo Hutter
  • Patent number: 6148107
    Abstract: A block based signal compression system, as for example for coding video signal, and employing quantization of codewords or transform coefficients includes circuitry for adaptively controlling the quantization. Adaptivity of quantization is made a function of several parameters. One parameter is coding cost or bandwidth, wherein coding cost is generated on a macroblock basis but averaged over a window of macroblocks centered on a macroblock currently to be quantized. Another parameter is block or macroblock motion attributes, wherein block motion attribut values are used to modify the quantizing function.
    Type: Grant
    Filed: August 18, 1997
    Date of Patent: November 14, 2000
    Assignee: Thomson multimedia S.A.
    Inventors: Xavier Ducloux, Philippe Guillotel, Ludovic Noblet, Pierre Ruellou
  • Patent number: 6118487
    Abstract: For compatible transmission of a television picture having an aspect ratio of 16:9 within a 4:3 system, transmission is effected in the letterbox format in accordance with the PALplus system specification. The receiver reconstructs the original picture with the aid of vertical filters and is able, furthermore, to suppress crosstalk interference from the luminance signals in the chrominance signals. To further improve the picture quality, the picture is displayed at a frame frequency of 100 Hz. For this purpose, the picture supplied at 50 Hz with line interlacing must be converted to a frame frequency of 100 Hz. Known concepts for PALplus decoding and 100 Hz conversion carry out these processes separately and in doing so require a great deal of memory space.
    Type: Grant
    Filed: May 1, 1997
    Date of Patent: September 12, 2000
    Assignee: Deutsch Thompson-Brandt GmbH
    Inventors: Gangolf Hirtz, Thomas Hollmann, Michael Maier
  • Patent number: 6100718
    Abstract: A circuit, for processing high frequency digital signals minimizes radiation interference by reducing voltage swings at the circuit input. This is accomplished by forming circuit input structures, which exhibit very low input impedances. An example of such input circuitry is a common gate amplifier with a diode coupling the source electrode of the common gate amplifier to ground potential and input signal applied to the source electrode. Output signal is derived from the collector of the common gate electrode which has a further diode as a load circuit.
    Type: Grant
    Filed: April 28, 1997
    Date of Patent: August 8, 2000
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventors: Phillppe Blaud, Albrecht Rothermel, Rainer Schweer
  • Patent number: 6088327
    Abstract: In the case of the OFDM method, a large number of modulated carriers are transmitted using frequency division multiplexing, a spectrum having a virtually rectangular shape being produced as a result of the large number of carriers. In order to separate the carriers from one another again in the receiver, a Fast-Fourier-Transformation is carried out, it then being possible to separate each carrier cleanly from the others provided the carriers are exactly orthogonal with respect to one another. The carrier orthogonality can, however, be disturbed by various causes. Furthermore, the wanted signal must be separated from the undesired adjacent channel signals by analog or digital filtering in the receiver. In order to improve carrier and channel separation, the selectivity of the FFT filtering can be increased by enlarging the number of FFT components. However, this normally leads to an undesirably sharp increase in the computation complexity.
    Type: Grant
    Filed: November 17, 1997
    Date of Patent: July 11, 2000
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventors: Claus Muschallik, Veit Armbruster
  • Patent number: 6081650
    Abstract: A transmitted high definition television signal is represented by a packetized datastream configured as a sequence of data fields (FIG. 1) with a non-uniform data rate due to unequal inter-data overhead information intervals. Each data field is prefaced by a Field Sync overhead segment followed by 312 packetized data segments each with associated overhead information (FEC). At a transmitter (FIG. 33), a transport processor (14) forms data packets with associated headers and exhibits uninterrupted operation at a constant uniform data rate, while supplying a packetized datastream to a network (17) which constructs sequential data fields by inserting the non-data overhead information into the datastream. The transport processor is advantageously operated at a constant uniform data rate without having to modify the original data field structure to accommodate the needs of the data field construction network.
    Type: Grant
    Filed: December 6, 1996
    Date of Patent: June 27, 2000
    Assignee: Thomson Licensing S.A.
    Inventors: Paul Wallace Lyons, Alfonse Anthony Acampora
  • Patent number: 6057891
    Abstract: A process for correcting the input-output correspondence of an analog-to-digital converter includes calculating the equation of the actual input-output correspondence, for known input values, during programmed conversion suspension periods. A comparison with the ideal conversion line subsequently makes it possible to calculate the necessary offset and gain corrections. The process is applied to the digital conversion of a plurality of component video signals.
    Type: Grant
    Filed: October 22, 1997
    Date of Patent: May 2, 2000
    Assignee: Thomson Licensing S.A.
    Inventors: Jean-Claude Guerin, Philippe Morel
  • Patent number: 6055270
    Abstract: A multiplexer system includes a multiplexer (20) having plural inputs (1-K) and an output (15); plural channel processors (10) each having a control input, a data input for receiving an input signal, a complexity output for providing a signal representing the complexity of an associated input data signal, and a data output for providing a constant bit rate data signal to an associated input of the multiplexer; and a bit rate allocator (30) responsive to the complexity representing signals for providing bit rate control signals to the associated control inputs of the channel processors (10) as a function of the complexity representing signals, such that a bit rate of an output data signal from a channel processor (10) is a function of the complexity of an associated input data signal and to the combined of the input data signals.
    Type: Grant
    Filed: October 11, 1996
    Date of Patent: April 25, 2000
    Assignee: Thomson Cosumer Electronics, Inc.
    Inventors: Mehmet Kemal Ozkan, Billy Wesley Beyers, Daniel Jorge Reininger, Kuriacose Joseph
  • Patent number: 6041079
    Abstract: A field/frame conversion method for compressed digital video, especially MPEG type video, having mixed field/frame mode macroblocks in the DCT domain utilizes a 1-D IDCT/DCT approach rather than the conventional 2-D IDCT/DCT approach. A vertical 1-D IDCT is performed on the DCT domain mixed field/frame mode macroblock to obtain a horizontal 1-D DCT domain macroblock. Thereafter, field/frame conversion is performed on the horizontal 1-D DCT domain macroblock to yield a field or frame mode horizontal 1-D DCT domain macroblock, depending on the required conversion. Finally, a vertical 1-D DCT is performed on the field/frame converted horizontal 1-D DCT domain macroblock to yield a 2-D DCT domain macroblock.
    Type: Grant
    Filed: June 30, 1998
    Date of Patent: March 21, 2000
    Assignee: Thomson Consumer Electronics, Inc,
    Inventor: Changhoon Yim
  • Patent number: 6028639
    Abstract: A process and apparatus for converting an MPEG-2 bitstream into an SMPTE-259 compatible bitstream is characterized by a frame rate converter which is selectively enabled to drop every 1001st frame of the incoming MPEG-2 bitstream depending on the input bitstream frame rate. If the input bitstream frame rate is other than 29.97 or 59.94 Hz, a frame dropper is enabled to discard every 1001st frame. The present converter can convert many different types of input bitstreams, such as all I types, IPIP types, or complex GOP types containing I, P, and B frames. The enabled frame dropper will drop either the I or P frame if it occurs as the 1001st frame, but if the 1001st frame is of the B frame type, the pixel information of the B frame is dropped. This produces a minimum in loss of information during the conversion. The format converter allows existing SMPTE-259 routing equipment to route and utilize MPEG-2 bitstreams, such as HDTV applications.
    Type: Grant
    Filed: December 19, 1997
    Date of Patent: February 22, 2000
    Assignee: Thomson Consumer Electronics, Inc.
    Inventors: Bhavesh Bhalchandra Bhatt, Ragnar Hlynur Jonsson
  • Patent number: 6023294
    Abstract: The invention is a process and apparatus for estimating a bit budget in a circuit for compressing digital data, especially digitized television signals. Signals represented by N-bit coded samples, are estimated based upon the probability of a bit of given order having a given value (0 or 1) out of M binary words representing M samples of the signal. An entropy calculation is performed on the basis of the probabilities corresponding to the N bits with the sum of all the entropies corresponding to the desired estimate.
    Type: Grant
    Filed: May 16, 1996
    Date of Patent: February 8, 2000
    Assignee: Thomson multimedia S.A.
    Inventor: Fathy Yassa
  • Patent number: 5987418
    Abstract: Dolby AC-3 and MPEG-2 audio permit the transmission of audio signals in packet form, via more than two independent audio channels. If a reproduction device has only a two channel audio decoder an external multi channel audio decoder may be used for multi channel audio reproduction. In this instance, packetized signal is received by a first decoder and is decoded for a first mode of reproduction and applied to a reproduction device. The received signal is unpacked in the first decoder and stored in memory. The stored signal is reformatted for application to a second decoder for decoding and reproduction according to a second mode of reproduction.
    Type: Grant
    Filed: December 4, 1998
    Date of Patent: November 16, 1999
    Assignee: Thomson multimedia
    Inventor: Jean Marc Gentit
  • Patent number: 5987073
    Abstract: A symbol timing recovery (STR) error detector includes a complex multiplier and a Gardner-type symbol timing error estimator for operation with carrierless amplitude phase (CAP) signals. Quadrature Ir and Qr signals from the system are input to the complex multiplier, which also receives signals from a numerically controlled oscillator operating at the CAP center frequency. The output of the complex multiplier is provided to the input of the Gardner STR error estimator. An added frequency shift allows the Gardner error estimator to function with CAP signals. The output from the error estimator is provided to a loop filter the output of which is provided to an oscillator which generates the symbol timing information for a symbol sampling network.
    Type: Grant
    Filed: March 27, 1997
    Date of Patent: November 16, 1999
    Assignee: Thomson Consumer Electronics, Inc.
    Inventor: Paul Gothard Knutson