Thomson Licensing S.a.

Thomson Consumer Electronics Inc.

Tian Jun Wang

Lauren A Christopher

Dong-Chang Shiue

Adolf D'Souza

Lauren Ann Christopher

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 ( ) for producing a datastream which is oversampled at twice the received symbol rate, and a digital demodulator ( ; FIG. ) with a data reduction network ( ) in a phase control loop. A segment sync detector ( ; FIG. ) uses an abbreviated correlation reference pattern to recover a twice symbol rate sampling clock for the digital converter ( ). A DC offset associated with the pilot component is removed ( ; FIG. ) from the demodulated signal before it is applied to an NTSC interference detection network ( ; FIG. ). The interference detection network includes a comb filter network ( ) responsive to a twice symbol rate sampled data datastream, and exhibits a sample delay dimensioned to avoid aliasing in the combed frequency spectrum (FIG. ), thereby increasing the effectiveness of NTSC co-channel interference detection.

Co-channel interference detection network for an HDTV receiver

An adaptive channel equalizer ( ) for processing a demodulated VSB signal containing terrestrial broadcast high definition television information operates adaptively in blind, training, and decision-directed modes. The VSB signal is characterized by a data frame format (FIG. 2) constituted by a succession of data fields each containing a data segment prefaced by a field sync segment. Equalization is expedited by recycling ( ) received training data through the equalizer more than once during a VSB data field after a field sync segment is detected.

Adaptive channel equalizer having a training mode

Demodulator for an HDTV receiver

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 (,) for producing a datastream which is oversampled at twice the received symbol rate, and a digital demodulator (,; FIG.,) with a data reduction network (,) in a phase control loop. A segment sync detector (,; FIGS.,) uses an abbreviated correlation reference pattern to recover a twice symbol rate sampling clock for the digital converter (,). A DC offset associated with the pilot component is removed (,; FIG.,) from the demodulated signal before it is applied to an NTSC interference detection network (,; FIG.,). The interference detection network includes a comb filter network (,) responsive to a twice symbol rate sampled data datastream, and exhibits a sample delay dimensioned to avoid aliasing in the combed frequency spectrum (FIG.,), thereby increasing the effectiveness of NTSC co-channel interference detection.

Network for eliminating DC offset in a received HDTV signal

Segment sync recovery network for an HDTV receiver

In a video signal processing system, a single adaptive passband equalizer is used to process a composite Quadrature Amplitude Modulated (QAM) signal encoded with high priority (HP) and standard priority (SP) components. The equalizer output is phase corrected by a de-rotator, and filtered to separate the HP and SP components. Error signals respectively representing HP and SP phase errors are developed. One of the error signals controls the operation of the de-rotator. Both error signals are used to generate updated coefficients for the adaptive equalizer. Afterwards the HP and SP components are decoded and combined.

Multiple QAM digital television signal decoder

In a high definition television signal encoder, high priority and standard priority digital data are each separated into quadrature I and Q components, spectrally shaped by digital filtering, and time division multiplexed to produce respective quadrature amplitude modulated signals of the 32-QAM type. The high priority QAM signal and the standard priority QAM signal exhibit different bandwidths and carrier frequencies. The high priority and standard priority QAM signals are combined in digital form to produce a prioritized dual 32-QAM digital signal before being conveyed to a single analog-to-digital converter and analog RF transmission networks.

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Indianapolis, IN, United States of America

Tian Jun Wang