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.

A blind scan system in a DVB-S system includes a spectrum parameter extractor to fetch and calculate a coarse carrier frequency offset and coarse symbol rate of a signal; a digital mixer to depend on the coarse frequency offset to shift the center of a spectrum of the signal to a position where a DC part of a working spectrum of a digital matched filter locates, so as to produce an offset signal; and an interpolator to perform a down-sampling on the offset signal according to the coarse symbol rate in order to improve the in-band signal-to-noise ratio of the digital matched filter and mitigate impacts due to adjacent channel interferences. Thus, the fine carrier frequency offset and fine symbol rate estimation can be performed accurately.

A FFT-based blind channel searching and estimation method, comprising the steps of waiting for a power-on signal from a DVB-S receiver, judging whether a complex of automatic gain control signals of the receiver have converged, producing a complex of data samples by utilizing the FFT, calculating energy after the FFT and accumulating the energy to be saved to the memory of the DVB-S receiver, detecting whether sample times exceed a predetermined value, filtering a complex of signal noises after accumulation with a filter, judging whether a channel of the channel has been searched, finishing searching and calculating to produce a symbol speed and a center frequency shift, and enabling a decoder action. The present invention is applied for a DVB-S receiver to effectively decrease the time required to complete a blind search and guarantees that an exact signal in a DVB-S receiver is found.

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 Saw Filter 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.

The invention discloses a multi-standard television receiver, comprising receiving ports, tuners and a main processor, wherein the receiving ports receive different television standard signals; the tuners modulate the different television standard signals into intermediate-frequency signals and output the intermediate-frequency signals to the main processor for processing; the receiving ports comprises an SATELLITE port for receiving DVB-S (Digital Video Broadcasting-Satellite) and DVB-S2 television signals, an AIR port for receiving DVB-T (Digital Video Broadcasting-Terrestrial) television signals, a CABLE port for receiving DVB-C (Digital Video Broadcasting-Cable) television signals and an ATV (Analog Television) port for receiving analog signals. The technical scheme of the invention contains ATV, DVB-T, DVB-C, DVB-S and DVB-S2 so that almost all European basic television standards are supported. With the five-in-one design, the requirements of different people in most European countries can be satisfied.

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 provides a blind scanning system for a DVB-S system. A control device of the system sets the analogue carrier frequency deviation of an analogue tuner according to a searching frequency range and judges whether signals are detected or not in a frequency spectrum output by a digital matched filter, if the signals are not detected, the control device sets the analogue tuner to enable the main components of a signal frequency spectrum to be detected to shift to the working bandwidth of the digital matched filter; the parameters of the signal to be detected are obtained, the digital carrier frequency deviation of the frequency spectrum is calculated according to the rough carrier frequency deviation of the frequency spectrum, and a digital mixer is set so as to carry out frequency shift on the digital baseband signal; and the digital mixer shifts the center of a detected signal frequency spectrum to the direct current part of the working frequency spectrum of the digital matched filter according to the setting of the control device. The invention also provides a blind scanning method for the DVB-S system. By adopting the method and the device, the carrier frequency deviation and the symbol rate can be accurately calculated, and quick blind scanning can be realized.

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.

The invention provides an intelligent set top box with a digital right management mechanism and an information security mechanism to solve the problems that an existing set top box is simplex in application function and can not share resources and information security can not be guaranteed when the existing set top box is applied to the internet due to the fact that the existing set top box does not have an information security mechanism. An intelligent terminal product based on big data publication and distribution is obtained on an embedded system platform of the intelligent set top box through research and development. A big data content receiving method based on three types of digital publication and digital distribution, namely, DVB-C, DVB-S and DVB-N, is fused to the embedded platform, and therefore an information security authentication mechanism and a digital certificate of a PKI+CPK dual-key management mechanism are achieved. A VPN and a wireless routing functional module based on WIFI are designed and obtained. Meanwhile, a U-Console intelligent platform system is designed and obtained in the embedded system platform based on a system with the version of android 4.0 or a version higher than android 4.0.

The invention discloses a Moderate Resolution Imaging Spectroradiometer (MODIS) moderate resolution digital signal receiving method, which comprises the steps of treating moderate frequency signals obtained through frequency conversion from a radio frequency end by Quadrature Phase Shift Keying (QPSK) digital demodulation, Viterbi decoding, frame synchronization, de-interleaving and Reed Solomon (RS) decoding; outputting data to a Personal Computer (PC) end; converting format of the data, thereby obtaining MODIS0 level of data product, wherein QPSK digital demodulation and Viterbi decoding are realized by a Digital Video Broadcasting-Satellite (DVB-S) demodulation chip; the MODIS moderation resolution digital signal receiving method is characterized by controlling and expanding the DVD-S demodulation chip by using a single chip and a programmable Field Programmable Gate Array (FPGA) chip, thereby realizing reception of moderate resolution digital signal of MODIS signals.

The invention provides a satellite searching system and a satellite searching method with a satellite signal mistake-locking prevention function, and relates to the communication field of the satellite. The satellite searching system comprises a microprocessor MCU unit, a high frequency head, a frequency converter, a demodulator and a positioning module; the high frequency head receives a satellite signal transmitted by an antenna feed source; the frequency converter performs amplifying and down conversion on the signal output by the high frequency head; the demodulator demodulates the signaloutput by the frequency converter into a standard transmission signal according to the transmission standard (DVB-S, DVB-S2, ABS-S) of the satellite signal; and the MCU unit obtains a signal quality value of the current satellite signal from the demodulator and drives the positioning module according to the signal quality value to enable the antenna to search the satellite automatically so as to complete satellite signal locking. By virtue of the satellite searching system, the problem of easy mistake locking (the antenna plane of the satellite antenna is not aligned to the corresponding satellite) of the automatically tacking satellite antenna can be solved, so that the satellite searching system can be applicable to a vehicle platform and a shipborne platform, and is low in use cost, simple in control, convenient to operate and high in stability.

The invention relates to a digital video broadcasting (DVB-S) receiving circuit with multiple inputs and a signal receiving method, which can receive the planet input signals provided by a plurality of low noise frequency alias demultiplier (LNB), to reduce the construction cost of the DVB-S system. The DVB-S receiving circuit comprises a selecting circuit and a bonding device, wherein the selecting circuit comprises a plurality of signal paths for receiving and transmitting a plurality of planet input signals, the selecting circuit triggers one of the signal paths according to a control signal to output one of the planet input signals, the bonding device bonds the signal paths into a single path to be connected with a DVB-S turner for following treatment.

A method for informing a user of the rotation of a dish in a Digital Video Broadcasting-Satellite system includes determining the duration of the rotation of the dish according to the angular velocity of the dish and the angle of the rotation; and outputting the duration of the rotation of the dish.

The invention relates to a DVB-S (digital video broadcasting-satellite) set top box compatible with various audio video signal interfaces and having a standby mode. The set top box comprises a signal strength detecting device, a uniform signal interface device and a power management device, wherein the power management device is connected with the signal strength detecting device to confirm whether or not the set top box enters into the standby mode according to the signal strength detected by the signal strength detecting device, and the uniform signal interface device is compatible with the connection of audio-video signals in a DVI (digital visual interface) form, an HDMI (high-definition multimedia interface) form and a Displayport form. After the set top box is used, the audio-video signals in various forms can be received, the receiving and the processing of satellite digital television broadcast signals can be stopped when the satellite digital television broadcast signals are very bad, and the set top box enters into a standby status, so that the unnecessary power loss can be avoided.

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.

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 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 isused 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.

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.

The invention provides a splicing packing method for a MAC frame of an Ethernet, belonging to the field of data communication, which solves the problem of integration of three networks in the prior art. The invention provides a splicing packing method for the MAC frame of the Ethernet. The method includes that splicing is carried through on the MAC frame after a gateway receives the MAC frame and adds marks and control information on the MAC data after splicing to combine a TS flow and transmit to an HFC network by a QPSK modulation module; a CM carries through QPSK modulation by a DVB-S tuner and combines into the step for the MAC frame to send to a PC according to the marks and control information in a packet. By adopting the scheme of the invention, digital video broadcast transmission of MAC data is realized and the problem that the access network is not unified in the integration of the three networks is solved.

The invention discloses a multifunctional signal monitor and a signal monitoring method. The monitor monitors an optical signal, a cable signal, a ground wave signal and a satellite signal through each monitoring module and performs analysis, and an MCU single-chip microcomputer receives a server instruction to instruct each monitoring module to operate. The analyzed signal indicators are stored in a data storage module and transmitted to the server through a network signal transmission module. The server performs data comparison and gives an alarm. The multifunctional signal monitor can monitor the signal intensity and signal quality of the DVB-S / S2, DVB-C, DVB-T / T2 and optical links of a station in real time, and transmits the relevant information of the output signals back. The server performs the data comparison and alarm, so a user can also view the uploaded relevant signal data through the terminal software to understand the state of a signal in real time and achieve the effect of multi-channel simultaneous monitoring.

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 present invention relates to a digital video-broadcasting satellite receiver, a quality and intensity instruction signal display method, the digital video-broadcasting satellite receiver includes a demodulator for receiving and down converting radio-frequency signal. An analog-digital converter samples the radio-frequency signal from the demodulator and converts the same into digital signal. A DC / AC eliminator receives the digital signal and eliminates the DC section of the digital signal, and generates a RXI signal and a RXQ signal. An automatic gain control unit receives the digital signal, generates and sends a control signal to the demodulator. A Fourier transformation unit for execute a Fast Fourier transformation to the RXI signal and the RXQ signal. A demodulator receives the RXI signal and the RXQ signal and generates a transport flow, where an intensity display signal of the received radio frequency signal is determined on the basis of the signal from the control unit, a quality display signal of the radio frequency signal is determined on the basis of signal from the transformation unit.

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.