38 results about "DVB-T2" patented technology

A method of transmitting data symbols via an Orthogonal Frequency Division Multiplexed (OFDM) symbols, includes forming data symbols into pairs, generating a first pair of modulation symbols for each of the pairs of data symbols, the first pair of modulation symbols forming first and second modulation symbols of an Alamouti cell, forming a first version of the OFDM symbols by modulating the sub-carriers allocated for carrying the data with the first and second modulation symbols of the Alamouti cells, and modulating the one or more pilot carriers of the first version of the OFDM symbol according to a predetermined pattern. The method also comprises generating a second pair of modulation symbols for each of the pairs of data symbols, the second pair of modulation symbols forming third and fourth modulation symbols of the Alamouti cell formed for the pair of data symbols in the first version of the OFDM symbol, forming a second version of the OFDM symbol by modulating the sub-carriers allocated for carrying the data with the third and fourth modulation symbols of the Alamouti cell, modulating the one or more pilot carriers of the second version of the OFDM symbols according to the predetermined pattern, and transmitting the first version of the OFDM symbol via a first antenna, and the second version of the OFDM symbol via a second antenna. For at least one of the pairs of data symbols, the sub-carriers, on which each of the first and second modulation symbols and the third and fourth modulation symbols forming the Alamouti cells, are separated within the first and second versions of the OFDM symbol by at least one other data bearing sub-carrier or one or more of the pilot carriers.

A transmitter and/or receiver according to the invention find application with the Digitial Video Broadcast-Terestrial 2 (DVB-T2) standard.

A data processing apparatus maps input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol. The data processor includes an interleaver memory which reads-in the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals. The interleaver memory reads-out the data symbols on to the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on to the sub-carrier signals. The set of addresses are generated from an address generator which comprises a linear feedback shift register and a permutation circuit. The linear feedback shift register has twelve register stages with a generator polynomial for the linear feedback shift register of R′_i[11]=R′_i-1[0]R′_i-1[1]R′_i-1[4]R′_i-1[6], and the permutation code forms, with an additional bit, a thirteen bit address. The permutation code is changed from one OFDM symbol to another, thereby providing an improvement in interleaving the data symbols for an 8K operating mode of an OFDM modulated system such as a Digital Video Broadcasting (DVB) standard such as DVB-Terrestrial2 (DVB-T2). This is because there is a reduced likelihood that successive data bits which are close in order in an input data stream are mapped onto the same sub-carrier of an OFDM symbol.

A receiver for detecting and recovering data from Orthogonal Frequency Division Multiplexed (OFDM) symbols. The OFDM symbols include within a repeating time frame a signalling OFDM symbol and one or more data bearing OFDM symbols, the signalling OFDM symbol including a pre-amble guard interval and a post-amble guard interval, the pre-amble and the post-amble guard intervals being formed by copying samples from a useful part of the signalling OFDM symbol in the time domain. The receiver includes a signalling and guard detector, which includes a correlator comprising a first branch which includes a first moving averaging filter, which is arranged to form pre-amble average correlated samples by averaging a value of a plurality of pre-amble correlated samples within a moving window, the plurality of samples averaged within the moving window corresponding to a temporal length of the post-amble (Tb), a second branch which includes a second moving averaging filter, which is arranged to form post-amble average correlated samples by averaging a value of a plurality of post-amble correlated samples within a moving window, the plurality of samples averaged within the moving window corresponding to a temporal length of the pre-amble (Tc), a combiner, which is arranged to combine the averaged pre-amble correlated samples and the averaged post-amble correlated samples to form output correlation samples. A post processing detector can detect the signalling OFDM symbol and moreover a synchronisation point derived from a centre of the signalling OFDM symbol with improved accuracy. The receiver finds application, for example, with DVB-T2 in detecting the P1 symbol.

A receiver detects and recovers data from Orthogonal Frequency Division Multiplexed (OFDM) symbols, the OFDM symbols including a plurality of sub-carrier symbols formed in the frequency domain and transformed into the time domain for transmission, the time domain OFDM symbols including a guard interval. The guard interval of the OFDM symbols is one of a plurality of predetermined temporal lengths and the guard interval is formed by repeating time domain samples of the OFDM symbol from useful samples of the OFDM symbols for a period corresponding to the guard interval from the OFDM symbols. The receiver includes a correlator operable to correlate the time domain samples at a separation determined in accordance with the useful samples of the OFDM symbols and for each of a plurality of possible guard intervals combining the correlated samples for a period equal to the guard interval, for a plurality of consecutively received OFDM symbols, to form for each of the possible guard intervals a correlation output value, and a guard interval identifier arranged to receive the output from the correlator and to identify one of the guard intervals used for the received OFDM symbols from the correlation output value for each of the plurality of possible guard intervals. Accordingly in a system such as DVB-T2, where the guard interval is provided in signalling data communicated with the OFDM symbols, the guard interval can be detected without or before the signalling data is detected, thereby reducing a time for detecting the data conveyed by the OFDM symbols or the guard interval and/or improving an integrity with which the guard interval and therefore the data can be detected.

A data processing apparatus maps input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol. The data processor includes an interleaver memory which reads-in the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals. The interleaver memory reads-out the data symbols on to the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on to the sub-carrier signals. The set of addresses are generated from an address generator which comprises a linear feedback shift register and a permutation circuit. The linear feedback shift register has ten register stages with a generator polynomial for the linear feedback shift register of R′_i[9]=R′_i−1[0]⊕R′_i−1[3], and the permutation code forms, with an additional bit, an eleven bit address. The permutation code is changed from one OFDM symbol to another, thereby providing an improvement in interleaving the data symbols for a 2K operating mode of an OFDM modulated system such as a Digital Video Broadcasting (DVB) standard such as DVB-Terrestrial2 (DVB-T2). This is because there is a reduced likelihood that successive data bits which are close in order in an input data stream are mapped onto the same sub-carrier of an OFDM symbol.

A data processing apparatus maps input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol. The data processor includes an interleaver memory which reads-in the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals. The interleaver memory reads-out the data symbols on to the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on to the sub-carrier signals. The set of addresses are generated from an address generator which comprises a linear feedback shift register and a permutation circuit. The linear feedback shift register has eleven register stages with a generator polynomial for the linear feedback shift register of R′_i[10]=R′_i−1[0]⊕R′_i−1[2], and the permutation code forms, with an additional bit, a twelve bit address. The permutation code is changed from one OFDM symbol to another, thereby providing an improvement in interleaving the data symbols for a 4K operating mode of an OFDM modulated system such as a Digital Video Broadcasting (DVB) standard such as DVB-Terrestrial2 (DVB-T2). This is because there is a reduced likelihood that successive data bits which are close in order in an input data stream are mapped onto the same sub-carrier of an OFDM symbol.

A system for determining the presence of, and information about, a DVB-T2 signal comprises means for providing a symbol with an active portion, providing a repetition portion and frequency shifting the repetition portion with respect to the active portion at a transmitter. At a receiver, the signal is multiplied by a complex conjugate of a delayed version of the signal to recover the symbol. The symbol may be referred to as a unique signal discovery symbol.

A receiver of a signal frame such as T2 frame used in a DVB-T2 system is provided. The receiver includes: a receiving unit configured to receive a frame including a preamble symbol in which a pseudo random noise (PN) sequence is inserted; a PN sequence detector configured to detect the PN sequence from the received frame; a controller configured to measure a start point of the preamble symbol and frequency offset of the PN sequence inserted in the preamble symbol, based on the detected PN sequence; and a preamble symbol detector configured to detect the preamble symbol according to the measured start point of the preamble symbol and the measured frequency offset of the PN sequence. Therefore, the receiver accurately measures the start point of the preamble symbol and the frequency offset and estimates a channel based on the PN sequence inserted in the preamble symbol.

Disclosed herein is a reception apparatus including: a spectrum inversion detection section configured to detect the occurrence or absence of spectrum inversion in a received signal complying with the Digital Video Broadcasting-Terrestrial 2 standard known as DVB-T2, using a P1 signal constituting the received signal; a spectrum inversion section configured to perform a spectrum inversion process on the received signal if the occurrence of the spectrum inversion is detected at least by the spectrum inversion detection section; and a demodulation section configured to demodulate the received signal having undergone the spectrum inversion process if the occurrence of the spectrum inversion is detected by the spectrum inversion detection section, the demodulation section further demodulating the received signal yet to undergo the spectrum inversion process if the absence of the spectrum inversion is detected by the spectrum inversion detection section.

DVB-T2 is the next generation standard for the terrestrial digital broadcast. There is the request of identifying the transmitters in the Single Frequency Networks mainly for testing purposes. This might be achieved by embedding a watermark sequence in the transmitters to identify them uniquely. However, the transmitters can also be deployed in SFN so they have to transmit exactly the same data. Therefore, the watermark has to be added at the radio signal. It connot be added at content level as it happens in other standard as, for instance, in cellular systems. The invention proposes two possible new methods to watermark the transmitter ID in the DVB-T2 signal. In both cases we assign orthogonal pilot sequences to different transmitters. In one case the sequences are added at very low power to ensure no loss in the data rate. This is a very attractive alternative, but it might require a much more expensive receiver. In the second case the sequences are added in a specific set of sub-carriers reserved for this specific use. This requires a better receiver synchronization and it also generates a small loss in data rate, but ensure a very simple and robust way to provide the transmitter identification.

The invention discloses a method of synchronizing precise timing of a DVB-T2 (Digital Video Broadcasting-Terrestrial 2) system. The method comprises the steps: extracting the pilot frequency of a first P2 symbol in the received T2 frame, performing pseudo random sequence correction, and carrying out IFFT (Inverse Fast Fourier Transform) to obtain channel impulse response; according to the average power and envelope of the channel impulse response, separating the effective path in the channel impulse response; making relation with a time domain P2 signal by using the time domain signal of the locally generated P2 pilot frequency according to the position of the effective path in the channel impulse response and the imaging position of the effective path, analyzing and judging the true position of the path in the channel impulse response; judging the characteristic of a channel by judging whether a path exists before a main path of a CIR, thus regulating the window of FFT (Fast Fourier Transform) in time domain by utilizing the minimal intersymbol interference principle. By utilizing the method, the computation amount and locking time can be greatly reduced, the synchronization accuracy of the precise timing can be improved, and the power consumption of the DVT-T2 system can be decreased.

This technique relates to a reception apparatus, a reception method and a program that allow for preventing erroneous detection of a predetermined signal, such as, for example, a P1 signal, included in a received signal, such as, for example, a DVB-T2 signal. A correlation calculation unit determines a correlation value between received signals each including a predetermined signal in which an original signal and a duplicate signal, which is obtained from a copy of at least part of the original signal, are located. An average power calculation unit determines an average power of the received signals. A normalization unit uses the average power of the received signals to normalize the correlation value, thereby determining a normalized correlation value. This technique can be applied to, for example, a case of detecting, from a received signal of DVB-T2, a P1 signal that is a preamble signal.

The invention discloses a method for correcting symbols regularly in a DVB-T2 system. In symbol synchronization, PI symbols regenerated in a receiver are utilized to correlate to received signals to find initial positions of OFDM symbols; segmentation operation is conducted on correlation operations; P2 pilot frequency time domain signals locally generated are utilized to correlate to the received signals according to the initial positions of the symbols; weighted average is conducted on five-point sliding results, and then the corresponding GI mode and the position of the maximum are found out. The method greatly reduces operation amount and operation cost and improves mode detection accuracy.

A time reference field is added to an L1 pre-signaling table of a broadcast DVB-T2 signal and location information is added to a Cell List Descriptor of a Network Information Table (NIT) of the broadcast DVB-T2 signal. A DVB-T2 receiver uses the time reference field and the location information from 5 the received broadcast DVB-T2 signal to determine its location.

Disclosed herein is a receiving apparatus including a preamble analyzer configured to receive a frame of DVB-T2 made up of an OFDM signal and analyze a preamble contained in the received frame; an offset detector configured to detect a fine offset and a coarse offset on the basis of the analyzed preamble; a carrier frequency corrector configured to execute carrier frequency correction on an OFDM time domain signal obtained by quadrature demodulation on the basis of the detected fine offset and the detected coarse offset; a determiner configured to determine whether the detection of the coarse offset has been completed; and a control signal outputter configured, if the detection of the coarse offset is determined to be completed, to output a control signal for feeding back the fine offset detected on the basis of an OFDM frequency domain signal obtained by FFT computation to the carrier frequency corrector.

The invention provides a high-practicability DVB-T2TVDongle digital television receiver. The high-practicability DVB-T2TVDongle digital television receiver comprises a control circuit board and an HDMI plug connector and a micro USB plug connector separately arranged at both end portions of the control circuit board; the HDMI plug connector and the micro USB plug connector are electrically fixed to the control circuit board by soldering; and the control circuit board is provided with a MSA7TXX series DVB-T2 low power consumption digital set-top box decoding chip. The high-practicability DVB-T2TVDongle digital television receiver also comprises a three-in-one signal line assembly used for connecting to the micro USB plug connector and performing data signal transmission; and the three-in-one signal line assembly includes a USB power supply line, an infrared receiving line and an RF antenna. In an actual application process, since the USB power supply line 131, the infrared receiving line 132, and the RF antenna 133 are combined in three lines, and one line realizes all functions, which brings great convenience to the user; therefore, the structure is simple and convenient, and doesnot occupy space; the cost is greatly reduced; and the packaging is simple.

The disclosure provides an apparatus for performing deinterleaving of a binary data stream and a DVB-T2 receiver, the apparatus comprising a mapping device and a semiconductor memory, the apparatus comprising a mapping device and a semiconductor memory; said mapping device comprising: an input interface arranged to receive said binary data stream and an output interface arranged to output a deinterleaved instance of said binary data stream; a row mapper, operatively connected to said input interface and said semiconductor memory, said row mapper being configured to group data received throughsaid binary data stream into "write" commands for said semiconductor memory; and a row deinterleaver, operatively connected to said semiconductor memory and said output interface, said row deinterleaver being configured to present deinterleaved data, retrieved from said semiconductor memory by means of "read" commands, to said output interface; wherein said semiconductor memory is an SDRAM memory;and wherein each of said "write" commands is an SDRAM write command for at least part of an SDRAM row, said SDRAM write commands being calculated such that said deinterleaved data can be written to and read out in SDRAM burst mode. By providing a row mapper that acts on the received data stream prior to its storage in the external memory, a data ordering can be achieved that permits the retrievalof deinterleaved data at a reduced bandwidth, in particular by using a burst-read operation on an SDRAM memory.