43 results about "DVB-S" patented technology

DVB-S / S2 transmodulator for VSAT units employing IP based communication. The transmodulator is optimized for VSAT networks, enabling legacy VSAT units to benefit from the developments of the advanced DVB-S2 standard. The transmodulator appears transparent to the legacy VSAT unit that is configured to operate with the older DVB-S standard. Some embodiments offer a unique feedback channel allowing the transmodulator to send messages and information to the ground station via the VSAT itself.

Digital TV receiving card and CAM card through CI interface respectively are connected to signal router. CI interface is connected to DVB-T or DVB-S receiving unit, and its signal through signal router and MPEG2 decoding module is sent to TV output interface. Operating steps are as following: inserting DVB-T or DVB-S receiving card into CI interface, detecting and configuring the board inserted by STB; selecting and connecting DVB-T or DVB-S by signal router; after being decoding and demodulating, signal, signal enters into another router, which forwards scrambled code stream through CI interface to CAM module; CAM filters scrambled code stream and sends processed data stream through CI interface to STB. Through source decoding unit in STB, original audio / video information obtained is sent to TV set for display.

The invention provides a program previewing method and system based on a digital television, wherein the method comprises: a set top box receives and analyzes the program mapping table of a corresponding channel program according to the channel switching command of a user; whether a previewing identifier exists in the private descriptor of the program mapping table is judged; if so, an identifier transmission packet in the private descriptor is transmitted to a condition receiving system, and the condition receiving system judges whether the identifier transmission packet is authorized; and if no, the previewing procedure is carried out. The invention correspondingly provides the program previewing system based on the digital television. The embodiment of the invention has the following beneficial effects: a program previewing function can be achieved in a unidirectional broadcast system of a digital video broadcasting-cable (DVB-C), a digital video broadcasting-terrestrial (DEVB-T) and a digital video broadcasting-satellite (DVB-S), thus programs can be preferably popularized; the operation is simple, additional management systems are not required, and the program previewing function can be achieved based on the existing conditional access (CA) system; and preview programs can be scrambled by virtue of an CA front-end system, thus the safety of program content can be enhanced.

A Digital Video Broadcasting-Satellite (DVB-S) receiver device includes a tuner, a SCART (Syndicat des Constructeurs d'Appareils Radiorécepteurs et Téléviseurs) connector and a system on chip (SOC). The tuner is for generating an output voltage. The SCART connector is for receiving the output voltage. The SOC is configured to receive a voltage signal associated with the output voltage outputted by the SCART connector, to digitize the voltage signal into a digital value, and to determine whether the digital value conforms with a default value so as to output a determination result.

A method and device for acquiring a channel with a frequency offset less than half symbol rate is applied but not limited to a DVB-S system. A target channel is selected to obtain a carrier frequency and a symbol rate for programming a tuner to obtain a digital baseband signal. A down-sampling factor is calculated based on the symbol rate for performing a down-sampling operation to obtain a down-sampling signal that passes through a digital matched filter to generate a filtered spectrum. A moving average and spectrum inversion is applied to detect location of the target channel and find two cross points thereby estimating a coarse carrier frequency offset for compensating the tuner and a coarse symbol rate. A fine carrier frequency offset and a symbol rate estimate are estimated for compensating and acquiring the target channel when the target channel is successfully detected.

The invention relates to a clock recovery system for a transmodulator allowing reception of a COFDM / DVB-T video signal encoded in the Terrestrial Digital Video Broadcasting format (DVB-T), via a terrestrial antenna and via a DVB-S like receiver suited to receive a QPSK / DVB-S video signal encoded in the Satellite Digital Video Broadcasting format (DVB-S).

The invention provides a novel radio frequency receiving tuner system. The system comprising the following modules: a signal link module which is in charge of amplification, frequency conversion and filtering of a radio frequency input signal, and a frequency synthesizer module which is in charge of generating a local oscillation signal needed for frequency conversion. Moreover, a digital control unit is arranged in the system so as to realize communication with a digital baseband module or a microcontroller. The novel radio frequency receiving tuner system has the following positive effects: supporting a complete single chip integrated satellite digital television tuner, needing no assistive devices, such as an external LNA (Low Noise Amplifier), a SawFilter and a crystal oscillation circuit; supporting multi-band receiving, such as 950MHz-1450MHz (ABS-S band), 950MHz-1750MHz (ABS-S expansion band) and 950MHz-2150MHz (DVB-S band); using simple 3.3V single supply in a power management system; being integrated with an I2C bus controller, and providing a software control interface; being integrated with automatic calibration circuits for frequency, gain, bandwidth and the like, and being free from manual testing and manual debugging.

A channel scanning method for Digital Video Broadcasting-Satellite (DVB-S) signals is provided. The method includes: scanning a radio frequency (RF) signal according to a normal frequency step; when the Nth channel is detected, obtaining a difference between a low boundary of an Nth channel and a high boundary of an (N−1)th channel; and, when the difference is within a predetermined bandwidth range, scanning the RF signal between the high boundary of the (N−1)th channel and the low boundary of the Nth channel according to a narrow frequency step. The normal frequency step is greater than the narrow frequency step.

The invention provides a system and a method for automatically detecting DVB-S signals and DVB-S2 signals. According to the system and the method, a mode control module is added in a demodulation module; whether received signals are DVB-S signals or DVB-S2 signals is detected and recognized automatically, and a corresponding signal type indication sign is given; and according to the signal type indication sign, one manner of a DVB-S processing manner and a DVB-S2 processing manner in the demodulation module is selected automatically, and received data are demodulated. Compared with a conventional scheme, the mode control module is added in the demodulation module, the design is simple, a mode of received signals is processed and judged automatically, the circuit design is simplified, resources are reused to the greatest extent, and the design cost and the system operation power consumption are reduced.

The invention discloses a five-in-one tuner for television signals. The five-in-one tuner comprises a radio frequency preprocessing module A, a down-conversion module, a digital video broadcasting-terrestrial / cable (DVB-T / C) / Asia television (ATV) demodulation module, a radio frequency preprocessing module B, a zero intermediate frequency processing module, a DVB-satellite / satellite-second generation (S / S2) demodulation module and a decoding module, wherein the radio frequency preprocessing module A is used for performing filtering and inter-level impedance matching on DVB-T / C and ATV signals; the down-conversion module is used for converting the DVT-T / C and ATV signals into low intermediate frequency signals; the DVT-T / C / ATV demodulation module is used for demodulating the low intermediate frequency signals, and outputting audio and video signals or a serial / parallel data stream; the radio frequency preprocessing module B is used for performing filtering and high frequency amplification on DVB-S / S2 signals; the zero intermediate frequency processing module is used for performing frequency conversion on the DVB-S / S2 signals to obtain I / Q signals; the DVB-S / S2 demodulation module is used for demodulating the I / Q signals; and the decoding module is used for decoding the data stream. The five-in-one tuner can realize the compatible demodulation and decoding output of DVB-T, DVB-C, ATV, DVB-S and DVB-S2 television signals.