TH25129B - Network for eliminating DC offset in received high definition television signals. - Google Patents

Abstract

DC60 (23/11/41) A vestigial sideband (VSB) modulated receiver containing terrestrial high-definition television information and a lead component consisting of an analog-to-digital input converter (19) for generating a stream sampled at twice the received symbol rate and a digital demodulator (22) with a phase-controlled reduction network. A segment sync detector (24) uses a short-coordinate correlation reference model to bring the twice-symmetric clock back to the digital converter (19). DC offsets associated with the lead component are removed (26) from the demodulated signal before being fed to an NTSC interference detection network (30). The interference detection network (30) consists of a fine-search filter network responding to the twice-symmetric stream and exhibits dimensionally desampled delays to avoid lag in the fine-search band. To improve the efficiency of NTSC co-occurrence interference detection, a vestigial sideband VSB modulated signal receiver is used, which comprises terrestrial high-definition television information and a lead component consisting of an analog-to-digital input converter (19) for generating a data stream sampled at twice the received symbol rate and a digital demodulator (22) with a phase-controlled reduction network. A segment sync detector (24) uses a shortened correlation reference pattern to clock the twice-symbol-rate sampled signal back to the digital converter (19). DC offsets associated with the lead component are removed (26) from the demodulated signal before being fed to the NTSC interference detection network (30). The interference detection network (30) consists of a fine-search filter network that responds to the twice-symbol-rate sampled data stream and exhibits dimensional sampling delays to avoid lag in the fine-search bands. This improves the efficiency of NTSC co-interference measurement.

Claims (7)

1. In a system for processing residual sidebar modulated (VSB) streams containing high-clarity video data is represented by a group of symbols that includes the aforementioned DC components. There are data frame formats that are composed by the data frames in the order in which Contains a sync field component that precedes many data segments that contain a sync component. Related segments In which the machine consists of An input network that responds to the above received signals for current generation. Modulated symbol data, sampled at a rate that is multiple of the rate. Symbols of the aforementioned streams A decoder network for providing the stream that has been decoded and gone. Also the output channel and compensation network That has been connected to the above input network and to the aforementioned decoder network. By working at the aforementioned sampling rates for The attenuation of the aforementioned DC components from the aforementioned demodulated symbolic stream where the aforementioned decoder network responds to the modulated output being modulated. Attenuation DC from the aforementioned compensation network. 2. In a system for processing residual sidebar modulated streams (VSB) obtained with high clarity video data is represented by a group of symbols that include DC components. The data frame format that is made up by the data frames in the order that Contains a sync field component that precedes many data segments. Processing method The signal consists of the following steps Generating a demodulated stream of symbols sampled at Rate, which is the multiple of the symbol rate of the above derived stream. Processing the aforementioned demodulated symbolic stream at a stroke rate The example above is to attenuate the aforementioned DC components to make the stream. Compensated symbols and decoding of the aforementioned compensated symbol streams. 3. Methods consistent with claim 2, whereby the aforementioned processing procedures It consists of the following steps Detecting the value of the DC component of the aforementioned stream Realization of DC compensation in response to known DC component values. From the aforementioned detection steps and the aforementioned compensation combination with the aforementioned DC components to reduce the aforementioned DC components. 4. In a system for processing the remaining sidebar modulated (VSB) streams that contain high-slope video data represented by a group of symbols. The foregoing information contains A data frame format that is made up of sequential data frames that contain synch-field components that It precedes a large number of data segments that have a corresponding sync segment. Where the machine consists of an input network that responds to the aforementioned streams for its implementation. The symbol stream is de-modulated, sampled data that is sampled. It is a multiples of the aforementioned signal-rate characteristics of the streams and the signal-processing paths, including basal-band subsystems operating at the stroke rate. The above example for processing symbol data streams has been demodulated at It has been sampled, where the aforementioned subsystems include one or more modulators, a search filter, and a DC compensation network. 5. Method consistent with claim 4, where the aforementioned received stream shows a symbolic frequency of 10.76 MHz and the multiple of the aforementioned sampling rate is 2, where the obtained data stream whip There are two examples per symbol. And the symbol data frequency 21.52 MHz 6. In the received modulated residual sidebar modulation (VSB) modulation system with high clarity video data represented by a group of symbols. The foregoing information contains A data frame format that is made up of sequential data frames that contain synch-field components that It precedes a large segment of data that has a corresponding syntax component. Where the machine consists of an input network that responds to the aforementioned streams for its implementation. Modulated symbol stream, sampled data, sampled It is made up of multiple symbol rates of the aforementioned streams and signal processing paths including the flared band subsystem operating at the stroke rate. An example above for processing the demodulated notation stream at Has been sampled as mentioned above Where the aforementioned processing paths include (a) an analog-to-digital converter that responds to the aforementioned streams of data. For generating a data stream, the sampled symbols are multiples of the rate. Symbols of the aforementioned streams (b) The demodulators respond to the sampled streams of the said symbols. For the provisioning of the stream, it has been sampled at the demodulated output and (c) the symbolic timing recovery network responding to the aforementioned outputs of the The above demodulation provides the sampling clock signal to the converter. Analog to the aforementioned digital 7. The method is consistent with claim 6, where the aforementioned received stream shows a notation frequency of 10.76 MHz and a multiple of the aforementioned sampling rate is 2, where the current Seizure information There are two examples per symbol. And the symbol data frequency 21.52 MHz