141 results about "DTV receiver" patented technology

A system that allows service providers, consumer electronic (CE) manufacturers or standards bodies to define flexible security policies (110) for the execution of downloaded applications (120) on digital television (DTV) receivers (160). The current receiver environment in which a software application is to be run is evaluated. For example, environmental factors such as time of day, date, channel currently tuned in, parental lockout status, grouping of major and minor virtual channels, and so forth, may be considered. An access controller (168) determines if the receiver's environmental factors satisfy the conditions for granting a permission to a downloadable application to allow access to the receiver functions (161), receiver resources and user private data. The security policy can be modified by installing or downloading a new security policy (110), or modified by a user with the provision of an appropriate interface. A Java code-implemented embodiment is disclosed.

A synchronization signal detection circuit and method of a digital TV (DTV) receiver are provided. The synchronization signal detection circuit determines a precise main path by determining powers in consideration of the influence of multiple paths near signals located at a peak value location and guarantees a stable operation of an equalizer by using error values output from a decoder to generate a synchronization locking control signal. A power signal based on the correlation of the received signal with a PN511 sequence is filtered to compensate for a dynamic multipath distortion (e.g., due to other multipath signals near signals located at a peak value location). The magnitude of the filtered power signal is then compared (e.g., with a predetermined threshold value) to determine the position of the main path (e.g., at the peak value location, or at a pre or post multipath signal location).

To increase the robustness of a broadcast DTV signal, complete (207, 187) Reed-Solomon forward-error-correction codewords are coded using binary linear block codes that reduce code rate by two or slightly less, enabling a DTV receiver to correct bit errors. Also, a DTV receiver can use a (15, 8), (16, 8) or (8, 4) block code to locate erroneous bytes for decoding (207, 187) Reed-Solomon code, so twice as many erroneous bytes can be corrected in a 187-byte data packet. The reduced code rate permits robust transmission of a 187-byte data packet in only two data segments and its super-robust transmission using a restricted symbol alphabet in only four data segments. This simplifies time-division multiplexing of data segments used for ordinary 8VSB transmissions with those used for robust and super-robust transmissions. Procedures to make legacy DTV receivers disregard data segments used for robust and super-robust transmission are disclosed.

A DTV receiver includes a tuner, an information detector, a demodulator, and a channel equalizer. The tuner receives a broadcast signal including valid data in which a known data sequence is periodically repeated. The information detector detects location information of the known data sequence and a coarse frequency offset value of the broadcast signal. The demodulator demodulates the broadcast signal by estimating a fine frequency offset value using the detected location information and by compensating a frequency offset of the broadcast signal using the course and fine frequency offset values. Finally, the channel equalizer compensates channel distortion of the demodulated signal using the detected location information.

A DTV signal is transmitted that avoids legacy DTV receivers regarding data segments used in other than ordinary 8VSB transmissions being mistaken for (207, 187) R-S FEC codewords that appear to free of byte error or can be corrected to appear so. The DTV signal is analyzed prior to its transmission, for detecting those data segments used in other than ordinary 8VSB transmissions that legacy DTV receivers could mistake for correct (207, 187) R-S FEC codewords or correctable (207, 187) R-S FEC codewords. Twenty bytes of each segment of data that could be so mistaken are modified to prevent such mistake. Complementing certain bits in the final twenty bytes of each segment of data is preferred if data are transmitted at one-half or one-quarter ordinary 8VSB code rate. Segments of control data, each pertaining to a respective future group of said segments of data, are transmitted in a further aspect of the invention for indicating which data segments are modified. These segments of control data can further include information concerning the type of modulation used in each data segment.

Certain embodiments of the invention may be found in a method and system for a vestigial side band (VSB), quadrature amplitude modulation (QAM), NTSC, out-of-band (OOB) receiver that is integrated in a single chip. The single chip integrated digital television (DTV) receiver provides plug and play DTV receiver capability for handling both North American digital cable television and digital terrestrial broadcast television compatible systems. The integrated DTV receiver may receive all standard-definition and high-definition digital formats (SDTV / HDTV) and an on-chip NTSC demodulator handles NTSC video. An output of the NTSC demodulator may be directed to an external broadcast television system committee (BTSC) or Zweiton M decoder, or it may be sent to an on-chip audio BTSC compliant decoder. The single chip integrated DTV receiver may also comprise an integrated out-of-band QPSK receiver, which may be adapted to, for example, handle a CableCard compliant with the CableCard Specification.

A television receiver includes circuitry that quickly derives a channel map for a DTV receiver. The apparatus includes tuner that is controlled by a processor in the television receiver to periodically test each channel frequency to determine the strength of the signal at that frequency. If the signal strength exceeds a threshold value, the channel map is updated to indicate that a channel exists at that frequency. The processor monitors the signal recovered by the tuner during normal television viewing for valid program information. If the processor does not detect valid program information for a channel in the program map, the threshold value used by the processor to build the channel map is raised. If the processor detects valid program information then information on the estimated noise level in the received DTV signal is used to update the threshold value. In one embodiment of the invention, the television receiver includes both a main tuner and an auxiliary tuner. The auxiliary tuner is controlled to periodically scan the television channel frequencies to update the channel map, even when the main tuner is being used by a viewer who is watching television.

A data structure, a digital television signal, a method of processing a digital television signal in a transmitter and a receiver, and a receiver are disclosed. A digital television signal for use in a digital television receiver for receiving program information from a broadcast transmitter, the digital television signal comprising an information table including a contents-type field indicating whether a type of contents of a program is advertisement. Therefore, a contents-type field capable of discriminating between actual program content data and advertisement content data is applied to standard information indicating content program information, resulting in the elimination of advertisement process problems associated with digital broadcast content data.

Method for changing channel information in a digital TV receiver which can deal with a channel cancellation / addition during broadcasting, including the steps of (1) determining a channel information of being changed from a broadcasting signal received at every preset time interval and storing the changed channel information, and (2) comparing the stored changed channel information and channel information stored already, for updating the channel information.

A digital television (DTV) receiver is provided, comprising: a demodulator that demodulates television signals and outputs equalizer training signals in the form of real (I) and imaginary (Q) data; a sync signal detector, and a phase compensator that offsets the phase of the I and Q data based on the phase offset signal and outputs phase adjusted I data under control of the lock control signal. The sync signal detector comprises: a correlator that correlates the equalizer training signals including the I and Q data; a power calculator that calculates the sum of the power of the correlated I and Q data; a comparator that compares (the sum) against a preset threshold and outputs a compare indication signal; a sync lock controller that monitors the compare indication signal and outputs a lock control signal; and a phase calculator that calculates a phase of the equalizer training signals based on the I and Q data and outputs a phase offset signal based on the compare indication signal.

A mobile digital TV (DTV) comprises a DTV receiver, a processor, a Global Positioning System (GPS) receiver and a memory for storing a data base of transmitter frequencies and transmitter locations for particular channels. The GPS receiver provides a location for the mobile DTV to the processor. The processor monitors distances between the location of the mobile DTV and at least two of the transmitter locations for a currently selected channel. Upon detecting that the mobile DTV is closer to a particular transmitting location than the other, the processor re-tunes the mobile DTV to the transmitter frequency of the closest transmitting for the currently selected channel.

Digital television system overlays subscriber two-way communication during broadcast program delivery to create virtual audience community. Individual or group billing and advertisement is personalized per DTV receiver program viewing and / or conferencing activity. Subscriber receiver includes camera and other media I / O device for multi-way video conferencing. Participants may be added or removed dynamically during programming or conferencing.

Implementation of Fast Information Channel (FIC) signaling when Chunks of FIC information span more than one sub-Frame of an M / H Frame is described. FIC signaling is advanced further at the digital television (DTV) transmitters than originally proposed, thereby eliminating need for substantial amounts of delay memory for coded M / H data in receivers for such data. Each FIC-Chunk includes a bit indicating when it is not applicable only to M / H Frames yet to be received but is also applicable to an M / H Frame being currently received. This facilitates reception being more quickly established after a change in DTV channel selection. Transmission Parameter Channel (TPC) signaling pertaining to the M / H Frame being currently received continues to the conclusion of the M / H Frame, so the total number of M / H Groups in each M / H sub-Frame is signaled to facilitate de-interleaving of the FIC signaling. Code combining of FIC Chunks is described.

A terrestrial digital television receiver includes a tuner, a microcomputer, and a demodulator. The microcomputer initially determines whether the DTV receiver is on, a power-on or power-off mode. If the DTV receiver is on the power-off mode, the microcomputer, control operation of the tuner to tune to a predefined emergency alert channel to receive a master guide table. The demodulator parses the master guide table. If the parsed master guide table indicates that a new emergency alert message is being received, the microcomputer automatically sets the DTV receiver on the power-on mode and controls operation of the tuner to tune to the emergency alert channel.

A DTV receiver includes a tuner, a demodulator, a known sequence detector, and a frequency domain equalizer. The tuner initially receives a broadcast signal including valid data in which a known data sequence is periodically repeated. The demodulator demodulates the broadcast signal, and the known sequence detector detects the known data sequence from the demodulated signal. The frequency domain equalizer compensates channel distortion of the demodulated broadcast signal in a frequency domain using the detected known data sequence. In addition, the DTV receiver may further include a time domain equalizer which compensates channel distortion of the time domain signal, or a noise canceller which removes a predicted noise from the time domain signal.

Systems and methods for processing signals in a communication system are disclosed and may include demodulating a wirelessly received inband signal and a wirelessly received out-of-band signal via a DTV receiver. One or more TV channels may be generated based on the demodulation of the wirelessly received inband signal and a wirelessly received out-of-band signal. The received inband signal may include a VSB signal, a NTSC signal and / or a QAM signal. The processing may also include determining whether the wirelessly received inband signal includes an analog signal or a digital signal. The digital signal may be error corrected, and the error corrected digital signal may be equalized. The analog signal may be decoded, and an audio output may be generated based on the decoding of the analog signal.

Disclosed is an antenna controller of a digital television receiver and a controlling method thereof including an antenna receiving channel signals of digital television broadcasting and having a directionality dependent on a control signal, a signal processing part tuning a wanted channel signal from the channel signals and processing the tuned channel signal as a wanted form, a detection part detecting state signals of the channel signal outputted from the signal processing part, a memory, when every new state signal is detected, storing the detected new state signal sorted with previously-detected state signals, a control part producing the control signal corresponding to an optimal direction of the antenna by comparing the new state signal to the previous state signals, and an interface part providing the antenna with the control signal, thereby enabling to increase the integration of the receiver.

A digital television signal for receiving program and system information protocol (PSIP) data, a method for processing the digital television signal, and a digital television receiver are disclosed. The digital television signal used in the digital television receiver in order to receive a program system information protocol (PSIP) data from a broadcast transmitter includes a rating region table containing the PSIP data. Herein, the rating region table includes a global rating value field defining a global rating value which is valid for all graphical rating regions, a rating region field defining a specific graphical rating region to be associated with the rating region table, and at least one local rating value field identifying a local rating value which is valid for the specific graphical rating region only.

An outdoor-antenna digital television receiver system has an electrically controlled remote tuner located close to the antenna. In response to a remote control signal, the remote tuner selects a particular radio-frequency digital television signal to be received, converts that RF DTV signal to an intermediate-frequency digital television signal of prescribed carrier frequency, and drives a downlead transmission line, preferably a coaxial cable. Indoors, the downlead transmission line is provided with an echo-free termination This echo-free termination may be in a “set-top” box that includes a frequency up-conveter that converts the IF DTV signal back to an RF DTV signal for reception by a conventional digital television receiver. Alternatively, the echo-free termination may be in a special DTV receiver without a local tuner. In such a special DTV receiver the IF DTV signal developed across the echo-free termination is supplied to circuitry for demodulation and analog-to-digital conversion, which circuitry supplies digitized baseband DTV signal.

Digital television system overlays subscriber two-way communication during broadcast program delivery to create virtual audience community. Individual or group billing and advertisement is personalized per DTV receiver program viewing and / or conferencing activity. Subscriber receiver includes camera and other media I / O device for multi-way video conferencing. Participants may be added or removed dynamically during programming or conferencing.

Carrier frequency estimation is completed in three phases: (1) receiver carries out coarse frequency estimation, (CFE) in order to locate frequency deviation correction within a small region; (2) non coherent auto frequency estimation (AFC) is carried out under obtained timing information is not completed; (3) coherent AFC is carried out under obtained timing information is completed i.e. the receiver enters into locking state, carrier frequency correction of data is completed by using a tracking loop in first order. The invention is realized at FPGA of Tsinghua DMB - T, ASIC version receiver. Favorable effect is obtained through actual try out broadcasting and testing, and performance is better than existing other system evidently.

Data to be more robustly transmitted within 8VSB broadcast DTV signals are turbo coded using parallelly concatenated convolutional coding (PCCC) and incorporated within the segments of data fields, the bytes of which are convolutionally interleaved before trellis coding and 8VSB symbol mapping. Packing the PCCC into payload fields of MPEG-2-compatible null data packets and Reed-Solomon coding the packets to generate the segments of data fields, the bytes of which are convolutionally interleaved, conditions legacy DTV receivers to disregard PCCC components not useful to them. Transversal packing turbo-coded Reed-Solomon codewords into the payload fields of MPEG-2-compatible null data packets increases the capability of those turbo-coded Reed-Solomon codewords to overcome burst errors. Repeated transmissions of the transversally packed turbo-coded Reed-Solomon codewords in whole or in part allows them to overcome protracted deep fades encountered during mobile reception of 8VSB DTV signals.

Disclosed is an image display method and apparatus capable of displaying best quality images even when image signals with a variety of aspect ratios are inputted. The image display method includes restoring a picture frame from a video data stream, detecting an aspect ratio of the picture frame, checking if the aspect ratio of the picture frame is matched with a predetermined aspect ratio of a digital TV receiver, adjusting a vertical size or a horizontal size of the picture frame if the aspect ratio of the picture frame and the predetermined aspect ratio of the digital TV receiver are different from each other, and format-converting the picture frame having the adjusted vertical size or horizontal size in accordance with a selected output format to output the format-converted the picture frame.

A digital broadcast signal for use in a digital television receiver includes a rating region table carrying rating information for multiple geographical regions, and a master guide table carrying information related to the rating region table. The master guide table includes a version number field defining a version number of the rating region table and at least one effective time field defining an effective time of the version number. The effective time represents a time after which a use of the rating region table is permitted. For example, it may be represented by a number of global positioning system (GPS) seconds since a coordinated universal time (UTC). The effective time field is included in a descriptor within the master guide table.

A timing recovery device in a digital television receiver using a VSB system is disclosed. In the present invention, the timing recovery device independently determines whether the detected hsync signal is reliable and operates if the detected hsync signal is reliable.

An emergency alert message is included in a cable broadcast signal. The emergency alert message includes major and minor details channel numbers associated with a details channel. A details channel number is configured based on the major details channel number when the minor details channel number is set to a null value. Next, it is tuned to a channel frequency of a digital cable channel corresponding to the details channel number when the details channel number exists in a digital channel number list. Alternatively, the emergency alert message includes a details channel source field which indicates whether a details channel is a digital or an analog channel. Then, it is tuned to a channel frequency of one of a digital cable channel and an analog cable channel based upon a value of the details channel source field.

An automatic gain controller (AGC) and method for use in a digital TV receiver having an IF amplifier, an RF amplifier, an analog to digital converter (ADC) connected to the IF amplifier, and a demodulator connected to the ADC, the AGC comprising: an input selector for selecting as feedback signal one of a digitized IF signal output of the ADC and a demodulated signal output of the demodulator; a signal detection unit for detecting the conditions of the feedback signal and outputting status signals; and a traffic controller for receiving the status signals and outputting control signals based on the status signals to an IF gain controller and an RF gain controller for independent gain control of the RF amplifier and the IF amplifier. The AGC and method further including hysteresis-curve-based switching for alternatively halting adjustments to IF gain while adjusting RF gain or halting adjustments to RF gain while adjusting IF gain.