34 results about "Digital terrestrial multimedia broadcasting" patented technology

The invention discloses a transmission method of time domain synchronous-orthogonal frequency division multiplexing (TDS-OFDM) based on a theory of compressive sensing and relates to the field of wireless communication. The method comprises the following steps: on the basis of self-correlation properties of a received training sequence and a local training sequence, obtaining parts of prior information of multi-path channels, and confirming a position of a non-interference area in the received training sequence according to the channel length of the multi-path channels included in parts of the prior information; according to parts of the prior information and on the basis of the theory of compressive sensing, calculating time delay of each path of the multi-path channels; and according to signals in the non-interference area and on the basis of a maximum likelihood algorithm, calculating coefficient of each path of the multi-path channels. According to the transmission method of the TDS-OFDM based on the theory of the compressive sensing, two technical problems that the TDS-OFDM is difficult to support high order modulation of 256 quadrature amplitude modulation (QAM) and the performance deterioration in dynamic channels is obvious are solved, and a strong theoretical and technical support is provided so that digital terrestrial multimedia broadcasting (DTMB) can catch up with and surpass the advanced international levels in key performance indicators of spectral efficiency, high-speed motion and receiving and the like.

The invention discloses a power-line-based digital terrestrial multimedia broadcasting (DTMB) transmission method and a power-line-based DTMB transmission device. The method comprises the following steps of: 1, generating or forwarding a DTMB broadcasting and television program signal, performing transmitter simulation processing on the signal, and coupling the signal to a power line for transmission by using a transmitter; 2, coupling and receiving the signal transmitted through the power line, performing receiver simulation processing on the signal, and performing channel decoding by using a receiver; and 3, performing signal source decoding on the signal subjected to the channel decoding, and playing or sharing the signal subjected to the signal source decoding in a multimedia terminal. A power line communication technology is used for finishing indoor multimedia broadcasting transmission and sharing, the conventional indoor multimedia transmission technology is effectively supplemented, the method is an effective method for the indoor coverage of a DTMB signal, and the method and the device have broad application prospect.

A Digital Terrestrial Multimedia Broadcasting (DTMB)-based carrier mode detection system includes first and second TPS decoders, first and second carrier calculators and a determinator. The first and second TPS decoders respectively receive NTPS input signals to thereby produce the corresponding NTPS mask signals and to respectively perform an absolute operation on the corresponding NTPS mask signals to accordingly select a maximum result as first and second absolute maximum mask signals for output. The first and second carrier calculators respectively receive NCS input signals and produce first and second absolute summation carrier signals. The determinator is based on the first absolute maximum mask signal, the first absolute summation carrier signal, the second absolute maximum mask signal and the second absolute summation carrier signal to accordingly determine that the carrier mode is of a multi- or single-carrier mode.

The invention provides a household multimedia gateway system based on the DTV-VLC key technology, and the system comprises a terrestrial digital information standard receiver which is used for receiving a DTMB (Digital Terrestrial Multimedia Broadcasting) signal emitted by an outdoor radio broadcasting base station or a DVB-C (digital video broadcasting) signal connected through a wired cable. The terrestrial digital information standard receiver is integrated with a DTMB / DVB-C demodulation unit and a PLC adaptive unit, and is used for receiving an home-entry DVB-C signal, carrying out the demodulation and decoding of the home-entry DVB-C signal, restoring a digital television video code stream, and modulating the digital television video code stream into a TDS-OFDM signal. The terrestrial digital information standard receiver comprises a tuner, a local oscillator drive analog-digital converter, an automatic gain control unit for the statistics of energy of received signals, an interpolation filtering unit, a channel equalizer, and a Hibert filter. The system effectively reduces the actual engineering implementation software and hardware complexity of a DTV-VLC integration broadcast system, improves the transmission efficiency, reduces the processing time delay, simplifies the production process of multimedia gateway equipment, and reduces the production cost.

The invention discloses a transmission method of time domain synchronous-orthogonal frequency division multiplexing (TDS-OFDM) based on a theory of compressive sensing and relates to the field of wireless communication. The method comprises the following steps: on the basis of self-correlation properties of a received training sequence and a local training sequence, obtaining parts of prior information of multi-path channels, and confirming a position of a non-interference area in the received training sequence according to the channel length of the multi-path channels included in parts of the prior information; according to parts of the prior information and on the basis of the theory of compressive sensing, calculating time delay of each path of the multi-path channels; and according to signals in the non-interference area and on the basis of a maximum likelihood algorithm, calculating coefficient of each path of the multi-path channels. According to the transmission method of the TDS-OFDM based on the theory of the compressive sensing, two technical problems that the TDS-OFDM is difficult to support high order modulation of 256 quadrature amplitude modulation (QAM) and the performance deterioration in dynamic channels is obvious are solved, and a strong theoretical and technical support is provided so that digital terrestrial multimedia broadcasting (DTMB) can catch up with and surpass the advanced international levels in key performance indicators of spectral efficiency, high-speed motion and receiving and the like.

The invention discloses a method for capturing the frame header PN of a digital terrestrial television system. When receiving a signal frame to recover data, a digital terrestrial multimedia broadcasting (DTMB) system simplifies relevant calculation of time domain by utilizing the group calculation of FFT and IFFT and judges whether a frame header PN sequence is successfully captured or not by comparing a relevant peak and a capturing threshold. By applying the method of the invention, a PN mode selected and used by the frame header of an identification signal frame can be quickly captured so as to provide necessary conditions for the follow-up process of a receiver; the speed of relevant calculation is improved and computational complexity is reduced; meanwhile, other treatment methods and logic circuits are not required to be added when the frame header rotates in phases of PN420 and PN945 modes, thus circuit structure is simplified so as to improve the speed for capturing the frame header PN in a digital terrestrial television broadcasting transmission system.

The invention discloses a power-line-based digital terrestrial multimedia broadcasting (DTMB) transmission method and a power-line-based DTMB transmission device. The method comprises the following steps of: 1, generating or forwarding a DTMB broadcasting and television program signal, performing transmitter simulation processing on the signal, and coupling the signal to a power line for transmission by using a transmitter; 2, coupling and receiving the signal transmitted through the power line, performing receiver simulation processing on the signal, and performing channel decoding by using a receiver; and 3, performing signal source decoding on the signal subjected to the channel decoding, and playing or sharing the signal subjected to the signal source decoding in a multimedia terminal. A power line communication technology is used for finishing indoor multimedia broadcasting transmission and sharing, the conventional indoor multimedia transmission technology is effectively supplemented, the method is an effective method for the indoor coverage of a DTMB signal, and the method and the device have broad application prospect.

The invention discloses a self-repairing SRAM (Static Random Access Memory) controller design for a DTMB (Digital Terrestrial Multimedia Broadcasting) demodulation chip. The controller comprises an error-address storage register group, an error detection circuit, a repairing circuit, an error reporting circuit and a reading-writing control circuit, wherein the self-repairing SRAM controller design is used for storing an error conventional SRAM address; the error detection circuit is used for carrying out error detection on the conventional SRAM, and storing the detected and error address into the error-address storage register group; the repairing circuit is used for mapping the error address into a redundant SRAM when a central module accesses the error address stored in the error-address storage register group and accessing the central module to the redundant SRAM; the error reporting circuit is used for carrying out error detection on the conventional SRAM after the repairing circuit maps the error address to the redundant SRAM, and reporting errors when detecting the error address; the reading-writing control circuit is used for finishing read-writing operation of the central module to the conventional SRAM and the redundant SRAM.

The invention relates to a solution to parallel encoding of the QC-LDPC (quasi-cyclic low-density parity-check) codes with three different code rates in a DTMB (Digital Terrestrial Multimedia Broadcasting) system. The solution is characterized in that a parallel QC-LDPC code encoder of the system mainly comprises four parts including a register, lookup tables, a bc-bit two-input exclusive-or gate and a b-bit two-input exclusive-or gate. The parallel QC-LDPC code encoder provided by the invention is compatible with multiple code rates, can fully use the functions of the lookup tables in the FPGA (field programmable gate array) logic resources to reduce the resource demand effectively under the condition of keeping the encoding speed unchanged, and has the advantages of being easy to control, consuming few resources and power, being low in cost, etc.

The invention relates to a scheme for encoding QC-LDPC (quasi-cyclic low-density parity-check) codes with three kinds of different code rates in a DTMB (digital terrestrial multimedia broadcasting) system. The scheme is characterized in that an encoder for the QC-LDPC codes of the system is based on a register sharing mechanism and mainly comprises five parts, i.e. a shared register part, a multifunctional shifter part, a parallel filter part, a linear feedback shift register part and a parallel rotate left accumulator part. The latter four function modules share sixty-two b-bit registers. The QC-LDPC encoder provided by the invention has the advantages that the memory is not needed, the QC-LDPC encoder is compatible with multiple code rates, the encoding time is not related to the code rates, the encoding speed can be obviously improved, the logic resource demands are effectively decreased, the encoding speed is fast, the resource consumption is small, the power consumption is small, the cost is low and the like.

The invention provides a transmission parameter signaling decoding system applied to digital terrestrial multimedia broadcasting, comprising an input signal estimation apparatus, a fast Hadamard transform apparatus, a shield apparatus and a character code index decision device. The system can be applied to a multi-carrier mode or a Single-carrier mode, can acquire input signals respectively from a frequency domain or a time domain, and provide the optimal transmission parameter signaling (TPS) decoding system architecture according to different conditions, for instance, whether the known Channel State Information is balanced with a channel or not.