75 results about "Digital tv broadcasting" patented technology

The system comprises three parts: adapter in single frequency network, GPS receiver, and modulator of supporting ground digital TV broadcasting in single frequency network. At central transmitting terminal, the adapter inserts MIP packets in transmission code stream. MIP packet carries synchronizing time label relevant to GPS receiver and system maximal time delay to each relay station etc. In each relay station, synchronization system detects M1P packets, reading out time label and maximal time delay, measuring time delay of received signal, calculating out additional time delay. According to the additional time delay, TS flow is delayed properly in order to make signal synchronization again among relay stations. The disclosed scheme is realized through FPGA, and is applied to ground digital multiple media broadcasting transmission system forwaded by Tsinghua Univ. Favorable effect is obtained through actual try.

The present invention provides a wireless redistribution system for terrestrial digital TV broadcasting applied to a TV receiver capable of receiving signals of a VHF band in addition to signals of a UHF band as a frequency band of terrestrial digital TV broadcast signals. The system comprises: a transmitter, into which terrestrial digital TV broadcast signals received by an outdoor antenna are inputted, for converting the frequency of the inputted terrestrial digital TV broadcast signals to a frequency of an unused channel of the VHF band collectively, and then amplifying and transmitting them wirelessly; and a receiver for receiving and amplifying signals transmitted from the transmitter, and then supplying them to the TV receiver.

The present invention relates to the field of digital information transmission technology. The hierarchical block product code (BPC) error correcting, encoding and modulation method includes: coding the input data code stream with different priority level in separate BPC code to obtain BPC stream, mapping the BPC stream based on definition to different bits of planisphere symbol of set modulationmode to obtain hierarchical modulation signal output with different antijamming capability. The present invention has the advantages of simple embodiment, more priority levels, powerful error correcting capacity and high reliability, and may be used in ground digital TV broadcasting system and other fields.

The present invention relates to an apparatus for transforming digital TV broadcasting signals into digital radio broadcasting signals and a method thereof. The apparatus includes: a transport stream generator for transforming TV broadcasting signals outputted from outside into digital TV broadcasting transport streams; a broadcasting transport format transformer for generating digital radio broadcasting transport streams by transforming the digital TV broadcasting transport streams in conformity to a digital radio broadcasting transport protocol based on a radio broadcasting schedule; a digital radio broadcasting multiplexer for multiplexing the generated digital radio broadcasting transport streams generated in the broadcasting transport format transformer; a modulating/up-converting unit for modulating the multiplexed digital radio broadcasting transport streams in a modulation method of digital radio broadcasting and up-converting frequencies of the modulated radio broadcasting signals into radio frequency (RF) signals; and a high-power amplifier for amplifying and transmitting the up-converted RF signals through a transmitting antenna.

The invention discloses a method of personal identification of digital TV broadcasting signal, which applies part or all of program content, time information and channel identification information of digital TV to generate personal identification code of a broadcasting TV signal on a transmission front end of the digital TV broadcasting signal, then the personal identification code of the broadcasting TV signal is placed in a self-defined data code flow which meets the standard of digital TV code flow and the self-defined data code flow reuses the transmission together with the former digital TV transmission flow; the illegal signal can be identified effectively through judging the legitimacy, effectiveness and integrity of the received content by selecting and detecting the personal identification code of the digital TV signal on a transmission receiving end of the digital TV broadcasting signal. Each part of information of personal identification code provided by the invention has a uniformed simple block structure, and the receiving end can carry out the analysis conveniently. The invention can reasonably choose the corresponding signature information to generate the personal identification code according to different safety protection requirements, thus realizing the higher performance cost ratio on the premise of guaranteeing the system requirements.

When a channel of a digital TV broadcasting is selected, a direction information of the channel, which is stored in a channel setting table, is set in a smart antenna and then, in a case of a signal absence state of a broadcasting signal or when a reduction of receiving signal intensity is detected, an optimal directivity direction, in which the broadcasting signal is reproducible and the receiving state of the wave is optimal, is determined by switching (scanning) the directivity direction of the smart antenna. And, the determined directivity direction is stored in the channel setting table as the direction information of a current channel and the directivity direction is set in the smart antenna.

A digital broadcasting receiver capable of receiving a plurality of types of digital broadcasting, for example, digital satellite broadcasting, digital ground wave broadcasting and digital CATV broadcasting. The digital broadcasting receiver includes a software utilizing demodulating section for demodulating a digitized intermediate-frequency signal, a memory for storing software to be used in the software utilizing demodulating section so that each digital broadcasting capable of being received is demodulated, and a control section for giving a command to the software utilizing demodulating section so that the software for demodulating each digital broadcasting is selectively used by the software utilizing demodulating section according to a setting made by a remote control transmitting unit or a key input section which is a setting input section.

The disclosed receive and decipher method for digital TV broadcast business comprises: a master terminal applies the copyright object of relative digital TBV broadcast business and/or program for the slave terminal; the latter receives and deciphers the relative business and/or program. This invention enhances flexibility for broadcast business.

The invention is a system framing structure for use in using the system framing module to implement process of time domain and frequency domain. The system frame is processed through the selector to select frequency domain processing mode or time domain processing mode. The system information for selecting both domains can be implemented by sending short PN code with different phases. The invention can make the ground digital TV broadcasting system to implement the integration process of time domain and frequency domain and to implement unified process for the single carrier and multi carrier.

A digital broadcasting system comprising of a digital broadcasting station, a set of digital broadcast receivers, and a switched network, wherein the digital broadcasting station transmits a digital signal to the set of digital broadcast receivers, and the digital broadcast receivers exchange error correction information with each other using the network to compensate errors in local receptions of the digital signal at each digital broadcast receiver location.

This invention relates to one method to automatically useful waveband searching method in digital broadcasting radio and comprises one receiving digital broadcasting emission digital signals transferring device, one digital broadcasting signals to receive the digital broadcasting, one play device, wherein, the method can search the band in the tuning band and displays the band when it is found to provide the users with relative frequency band in on frequency codes.

A digital TV receiving device includes a control circuit board and a TV tuner; a built-in signal receiver in the digital TV receiving device receives AV signals transmitted by digital TV broadcasting system; the TV turner decodes and modulates those AV signals, and then transmits modulated/restored digital signals to an externally connected information host to output for presentation.

The invention relates to a multimode digital television exciter, which comprises a channel encoding unit, a digital precorrection unit, a digital/analog (D/A) conversion unit, an orthogonal modulation unit, a broadband local oscillation unit, a power regulation and amplification unit and a control unit, wherein the channel encoding unit is a multi-standard channel encoding unit; and the digital precorrection unit is a multi-standard digital precorrection unit. Therefore, digital television standards, such as digital terrestrial multimedia broadcasting (DTMB), integrated services digital broadcasting (ISDB)-television (T), and digital video broadcasting (DVB)-T/H are realized through the multi-standard channel encoding unit; the standards can be switched in real time, and have extremely high capacity expandability; and furthermore, digital television standards and mobile television standards which are used in the whole world can be realized.

Provided is a modulation apparatus that can reduce time delay of on-channel repeaters in a terrestrial digital television broadcasting system. The time delay is caused by a filter during the modulation operation in the on-channel repeaters. The modulation apparatus of the present research includes: a baseband signal forming unit for forming a baseband signal by combining the output signals of an equalization unit with the pre-defined field/segment synchronization signals in the on-channel repeaters; a pilot inserting unit for inserting a pilot signal to the baseband signal; an up-sampling unit for up-sampling the baseband signal with the pilot signal; a VSB filtering unit for filtering the up-sampled baseband signal based on a Window technique and/or an Equi-Ripple filter to thereby form an in-phase (I) signal and a quadrature (Q) signal; an up-converting unit for up-converting the frequencies of the filtered I and Q signals to frequencies of an intermediate frequency (IF) band; an adding unit for adding the up-converted I and Q signals and converting a resultant signal into a digital VSB signal of the IF band; and a digital-to-analogue converting unit for converting the digital signal of the IF band to an analogue signal.

The invention discloses a reception apparatus and an antenna switch circuit of same and a tuner module. PND and portable TV which are employed for receiving digital TV broadcasting used for switching onboard external connected antenna and built-in antenna do not require large antenna switching IC and antenna switching control signal. A diode switch in replacement of the antenna switch IC is disposed and configured to perform switch with the on/off of a power source which is provided with LNA for provision for the external connected antenna. Therefore, the selection of any of the two antennae can realize simplification of components in usage and control signals and minimization of apparatus.