Abstract: Chopping techniques that suppress fold-back into the signal band and spreads the offset across the spectrum are described. By using various techniques, chopping may be performed with a variable frequency clock to spread the offset across the signal spectrum. Spreading the offset across the signal spectrum means that there are no longer large spurious tones at a few frequencies.

Abstract: A microelectromechanical gyroscope includes a support structure, a driving mass movable according to a driving axis; and an oscillating microelectromechanical loop. The microelectromechanical loop has a resonance frequency and a loop gain and includes the driving mass, a sensing interface that senses a position of the driving mass, and a gain control stage that maintains a modulus of the loop gain at a unitary value at the resonance frequency. The gain control stage includes a sampler and an transconductance operational amplifier in an open-loop configuration. The sampler acquires samples of a loop signal from the sensing interface in a first operative condition and transfers them to the transconductance operational amplifier in a second operative condition. The sampler decouples the transconductance operational amplifier from the sensing interface in the first operative condition and in the second operative condition.

Abstract: Dual mode filters having two reconfigurable multi-stage filters. In a dual band mode, each reconfigurable filter filters an input signal in a different band using every filter stage. In a single band mode, both reconfigurable filters are effectively divided into two sub-chains that include either the odd-numbered filter stages or the even-numbered filter stages. Together, the four sub-chains in the single band mode filter an input signal in a single band with a higher parallelization than each reconfigurable filter in the dual band mode. In some embodiments, the dual mode filter is a decimation filter. In other embodiments, the dual mode filter is a resampling filter. In still other embodiments, the dual mode filter is an interpolation filter.

Abstract: A method for precoding to mitigate nonlinear distortions and a precoder for performing the same are disclosed. The precoder for mitigating distortions of a communication signal may include a filter configured to generate a filtering signal based on a third signal and filter coefficients corresponding to a selected signal generated based on a first signal, a second signal, and the third signal, and a modulo operator configured to generate the third signal by performing a modulo operation on the second signal, wherein the second signal is generated based on the first signal and the filtering signal.

Abstract: A method is disclosed for mitigating phase noise at high frequencies in 5G and 6G. Quadrature modulation schemes, in which orthogonal branches are amplitude modulated, are susceptible to phase noise which rotates the branches, causing demodulation faults. Disclosed is a single-branch reference signal that can mitigate phase noise. The transmitter can transmit a particular resource element having a normal amplitude in one branch, and zero amplitude in the orthogonal branch. The receiver can then measure the amplitudes of the particular resource element as-received (with phase noise), and determine a phase rotation angle according to a ratio of the two branch amplitudes. The receiver can then correct the branch amplitudes of each message element, and thereby negate the effect of the phase noise. The disclosed procedures can thereby make high-frequency, high-reliability communication feasible, at extremely low cost.

Abstract: The present application proposes a method for receiving a demodulation-reference signal (DM-RS)-based downlink data signal from a base station by a terminal in a multiple-antenna-based wireless communication system. Specifically, the method comprises the steps of: receiving information relating to a linear coupling coefficient of a DM-RS antenna port from the base station; and receiving, from the base station, the downlink data signal to which a precoder for mapping the signal to a reference DM-RS antenna port and at least one auxiliary DM-RS antenna port among a plurality of DM-RS antenna ports is applied, wherein the precoder is to map the downlink data signal to the reference DM-RS antenna port and map the downlink data signal to the at least one auxiliary DM-RS antenna port by applying the linear coupling coefficient.

Abstract: System and method of adapting thresholds for constellation selection based on statistic distributions of received data symbols. To determine an adapted threshold, an expected ratio of received symbols with values in a certain range is preset based on an expected statistic distribution of data symbols across the multiple constellations. A first and a second ratios are defined based on the expected ratio, the first ratio being the expected ratio minus an error ratio and the second ratio being the expected ratio plus the error ratio. A first value is determined which makes the received symbols in a firs range to constitute the first ratio of a set of slicer inputs. A second value is determined which makes the received symbols in the second range to constitute the second ratio of a set of slicer outputs. The adapted threshold is then obtained based on the first and the second value.

Abstract: A wireless device receives a frequency division multiplexed (FDM) symbol of constituent equalized FDM data subcarriers. A modulation scheme constellation diagram is subdivided into two or more regions. For each of the regions, a subset of the subcarriers that fall within the region are extracted and a respective region-specific CPE estimate is computed thereon. The respective region-specific CPE estimates are averaged to produce an overall CPE estimate used to compensate the subcarriers. Furthermore, a first CPE estimate is computed using pilot symbols embedded in a first received FDM symbol and is used to compensate the subcarriers. A following second FDM symbol that has no embedded pilot symbols is compensated using the first CPE estimate, and a second CPE estimate is computed using a blind estimation method on the second FDM symbol compensated subcarriers, which are compensated using the second CPE estimate.

Abstract: A method for clock recovery that may include obtaining an output signal from a phase locked loop (PLL) device. The method may further include determining, using a digital phase detector, the output signal, and a transmitter clock signal, an amount of phase difference between the output signal and the transmitter clock signal. The method may further include filtering, using a phase rotator and a digital accumulator, a portion of the amount of phase difference from the output signal to generate a filtered signal.

Abstract: A method of processing a digital television (DTV) signal is disclosed. Herein, the DTV signal is generated by performing Reed-Solomon (RS) encoding on additional data, multiplexing the RS-encoded additional data with main data, RS encoding the multiplexed additional and main data, interleaving the RS-encoded additional and main data, trellis encoding the interleaved additional and main data, and transmitting a Radio Frequency (RF) DTV signal including the trellis-encoded additional and main data. The method to process the DTV signal includes receiving the DTV signal including the additional data multiplexed with the main data through an antenna, in which signaling information is periodically inserted in the additional data. The received DTV signal is demodulated including performing channel equalization on the demodulated DTV signal. Trellis decoding is performed on the channel-equalized DTV signal.

Abstract: Provided is a receiver for processing VSB signal. The receiver includes a first equalizer/decoder unit and a second equalizer/decoder unit. The first equalizer/decoder unit performs a first equalizing operation, first TCM decoding and first RS decoding on a received symbol to output a first dibit. The second equalizer/decoder unit performs a second equalizing operation, second TCM decoding and second RS decoding on the received symbol to output a transport stream. The first dibit is provided as a priori information for a soft-decision operation of the second TCM decoding.

Abstract: A method for remotely and dynamically controlling adjacent satellite interference comprising monitoring one or more off-axis signals emitted by one or more remote transmitters; determining whether one or more of the off-axis signals is creating adjacent satellite interference (ASI), off axis emissions and inband interference that is higher than a predetermined level of acceptable interference, and transmitting a control signal to at least one of the one or more remote transmitters in response to the determination that the one or more off-axis signals is creating interference that is higher than the predetermined level of acceptable interference, the control signal initiating an adjustment to one or more transmission parameters of the one or more remote transmitters such that interference resulting from the one or more off-axis signals emitted by the one or more remote transmitters is reduced or eliminated.

Abstract: A carrier recovery device and a carrier recovery method are provided. The device includes a phase detection module, a computation module, a phase angle adjustment module, a loop filter, and a conversion module. The phase detection module receives an IF signal, and detects a sine and a cosine signals corresponding to the IF signal. The computation module receives the sine and the cosine signals, and computes a phase angle between the sine and the cosine signals. The phase angle adjustment module adjusts the phase angle according to one of the sine and the cosine signals and a threshold. The loop filter generates a frequency offset angle according to the phase angle. The conversion module generates a sine and a cosine parameters according to the frequency offset angle, and transfers the sine and the cosine parameters to the phase detection module.

Abstract: A receiver is an ATSC (Advanced Television Systems Committee)-receiver and comprises a pseudo-tone based carrier tracking loop and symbol timing recovery loop comprising one, or more, detectors for providing at least two pseudo tone (PST) signals. The first PST signal drives the carrier tracking loop and the second PST signal drives the symbol timing recovery loop. The detector provides the first PST signal such that the first PST signal is determined as a function of carrier offset excluding symbol-timing offset; and provides the second PST signal such that the second PST signal is determined as a function of symbol timing offset excluding carrier offset.

Abstract: A method of detecting a communication mode is provided to rapidly detect which one of near field communication (NFC) protocols includes a communication frame pattern of data provided to a receiving device. The method includes receiving a communication frame pattern of data transmitted from an NFC initiator after synchronizing the communication frame pattern with a predetermined sampling clock. The detection of the communication mode may be done by analyzing a start pattern out of the communication frame pattern. Since a communication mode is rapidly detected and data is automatically received without performing an additional operation to set the communication mode, operation performance of a receiving device is improved.

Abstract: A diversity receiver configured to receive digital signals, including a first modulator configured to receive a first signal and modulate the first signal to first data, a second modulator configured to receive a second signal and modulate the second signal to second data, a path aligner configured to detect starting points of the first data and the second data and generate a control signal for synchronizing the first data and the second data, and an equalizer/decoder configured to synchronize the first and second data and to generate a signal to noise ratio and an equalizer output by a recursive equalization operation for the diversity signals thus synchronized.

Abstract: To quickly and robustly detect the presence of an incumbent user and rapidly relinquish the spectrum to the incumbent user when necessary, carrier recovery is performed in a receiver of the secondary user's cognitive or software radio prior to performing correlation detection with an upsampled reference signal to correct for large frequency offsets and improve the performance of the correlation detector. To detect a received signal, a pilot value is added to a reference signal. The reference signal is upsampled to a sampling frequency of the received signal. The upsampled reference signal is correlated with a demodulated baseband signal to produce a correlation value. It is then determined whether the received signal is present if the correlation value is greater than a predetermined detection threshold value.

Abstract: A digital television (DTV) transmitter and a method of coding data in the DTV transmitter method are disclosed. A pre-processes enhanced data by coding the enhanced data for forward error correction (FEC) and expanding the FEC-coded enhanced data. A data formatter generates enhanced data packets including the pre-processed enhanced data and inserting known data to at least one of the enhanced data packets. A first multiplexer multiplexes main data packets with the enhanced data packets, and a data randomizer randomizes the multiplexed data packets. A Reed-Solomon (RS) encoder RS-codes the randomized data packets by adding first parity data, and a data interleaver interleaves the RS-coded data packets. A trellis encoder trellis-encodes the interleaved data packets, wherein the trellis encoder may be initialized when a known data sequence is inputted thereto.

Abstract: A method for receiving a broadcasting signal and a broadcasting signal receiver are disclosed. Even when a cell is changed while an emergency alert is output, the emergency alert can be continuously output using emergency alert table information included in the broadcasting signal and channel information of the cell. The emergency alert table information may include a cell identifier and the channel information of the cell may include virtual channel information of the cell.

Abstract: One embodiment sets forth a method of scanning a frequency channel, which includes receiving a radio-frequency signal in a selected frequency channel, performing a carrier recovery process, and evaluating a control signal generated during the carrier recovery process to determine the presence of program content in the selected frequency channel.

Abstract: A method and apparatus for aligning I- and Q-signals in a quadrature receiver based on an squared signal. A correction is evaluated in an iterative manner by finding an average of the squared signal. The average squared signal may be the received signal, in which case the iterations are applied in a feed forward manner. Alternatively, the average squared signal is the aligned signal in which case the iterations are applied in a feed back manner. The correction may include the evaluation of an normalization or, in the feed back case, this can be implicitly included in the manner in which the iteration is applied. Various parameters to the iteration can be set to accommodate the operating environment of the receiver and characteristics of the received signal.

Abstract: In an apparatus and method, time-varying signals are processed and encoded via a frequency domain linear prediction (FDLP) scheme to arrive at an all-pole model. Residual signals resulted from the scheme are estimated and transformed into a time domain signal. Through the process of heterodyning, the time domain signal is frequency shifted toward the baseband level as a downshifted carrier signal. Quantized values of the all-pole model and the frequency transform of the downshifted carrier signal are packetized as encoded signals suitable for transmission or storage. To reconstruct the time-varying signals, the encoded signals are decoded. The decoding process is basically the reverse of the encoding process.

Abstract: A single sideband mixer is constructed with digital logic elements such as T-type flip-flops and inverters and with FETs, and the resulting mixer circuit simultaneously improves control over the frequency resolution, noise floor and operating frequency range. The use of this group of elements also allows the mixer circuit to be easily realized in an integrated circuit.

Abstract: Systems and methods of digital interface translation are described. One embodiment of the invention includes multiple receiver lanes, where at least one of the receiver lanes is configured to receive a data channel at a first data rate and encoded in accordance with an input digital interface standard, an auxiliary channel input configured to receive an auxiliary data channel, and a single transmitter lane configured to output a single data channel at a second data rate and encoded in accordance with an output digital interface standard.

Abstract: Different sets symbols are precluded at prescribed times in time-dependent trellis coding. This increases the distances between different individual symbols as well as the distances between trellis codes, which increases the robustness of data transmission. The symbols that are precluded in this time-dependent trellis coding are determined in advance according to a prescribed pattern, which pattern does not depend on the history of previous symbols. The Viterbi decoder used for trellis decoding in a receiver can be designed to take advantage of knowledge concerning which different sets of symbols are precluded at prescribed times.

Abstract: In a frequency converting system, an input signal x(t) is supplied to a signal branching section for dividing a predetermined frequency domain into M bands, extracting signal components of the respective divided bands. The respective signal components and local signals each including a frequency difference corresponding to a predetermined intermediate frequency with respect to a center frequency of each band are input to a frequency converting part. The signals of the respective divided bands are converted into signals of intermediate frequency bands each including the predetermined intermediate frequency as the center frequency, the conversion outputs are sampled by using a common clock signal, whereby the conversion outputs are converted into digital signals. Further, after being subjected to phase correction processing, the digital signals are subjected to frequency conversion and combination processing by a signal regeneration part.

Abstract: A binarization circuit includes a comparator that outputs a signal according to a differential voltage between the input and reference voltages. The first charging-discharging circuit generates a first voltage. The second charging-discharging circuit generates a second voltage. The control circuit compares the differential voltage with the threshold voltage, and switches between turn-on and turn-off of the second charging-discharging circuit based on a difference between the differential voltage and the threshold voltage. A sum of the reference and first voltages of the preceding clock is supplied to the comparator when the second charging-discharging circuit is turned off. A sum of the reference and the first and second voltages of the preceding clock is supplied to the comparator when the second charging-discharging circuit is turned on.

Abstract: A transmitter for transmitting data in a communication system includes: a serial/parallel (S/P) conversion unit configured to convert data into an I signal and a Q signal; multiplication units configured to multiply the converted I and Q signals by orthogonal sequences, respectively; conversion units configured to Hilbert-transform the I and Q signals multiplied by the orthogonal sequences; addition units configured to add the I and Q signals multiplied by the orthogonal sequences and the Hilbert-transformed Q and I signal, respectively; and an intermediate frequency (IF)/radio frequency (RF) unit configured to up-convert the added I signal and the added Q signal and transmit the converted I and Q signals.

Abstract: An early-late gate based ADC timing approach is described for performing early-late gate timing recovery despite the presence of multipath signal distortion. Multipath conditions may severely distort Barker correlator magnitudes generated for taps within two taps of a determined bit synchronization time. Exemplary embodiments of the described approach may combine Barker correlator magnitudes for several receive chains to calculate the timing error correction corresponding to a difference of early and late taps. The approach may be used to increase the size and stability of Barker correlator magnitudes generated for taps far away from a determined bit synchronization time.

Abstract: An E8-VSB reception system, apparatus for generating data attribute and method thereof, and apparatus for channel encoding and method thereof are disclosed. In the present invention, E8-VSB data resulting from multiplexing a plurality of enhanced data encoded at different coding rates with main data is received. And, the main data and a plurality of the enhanced data are identified to be modulated from the received E8-VSB data. In particular, by generating M/E packet attribute information, enhanced packet attribute information, enhanced byte attribute information and E8-VSB symbol attribute information from the E8-VSB data attribute generating apparatus, the channel decoding apparatus can correctly identify to decode the main data, ½ enhanced data and ¼ enhanced data from one another.

Abstract: A digital broadcast transmitting/receiving system and a signal processing method thereof that can improve the receiving performance of the system. A digital broadcast transmitter has a randomizer to randomize an input data stream which has null bytes being inserted at a specified position, a multiplexer to output a data stream formed by inserting specified known data into the position of the null bytes of the randomized data stream, an encoder to encode the data stream outputted from the multiplexer, and a modulator/RF-converter to modulate the encoded data, RF-convert the modulated data and transmit the RF-converted data. The receiving performance of the digital broadcast transmitting/receiving system can be improved even in a multi-path channel by detecting the known data from the received signal and using the known data in synchronization and equalization in a digital broadcast receiver.

Abstract: A communication signal receiver includes a feed-forward filter and a coefficient adjusting circuit. The feed-forward filter generates an estimated imaginary-part component signal according to a real-part component of a complex data signal by using tap coefficients of the feed-forward filter. The coefficient adjusting circuit adjusts the tap coefficients of the feed-forward filter according to a control information, wherein the control information comprises a phase error information. The phase error information changes as a phase of the complex data signal changes, wherein the phase is adjusted or not adjusted by the coefficient adjusting circuit.

Abstract: An apparatus for recovering carrier wave in digital broadcasting receiver and a method therefore are disclosed which are capable of easily detecting and correcting frequency offsets of carrier wave without recourse to a pilot signal in a digital broadcasting receiver receiving a broadcasting signal of vestigial sideband (VSB) modulation system, thereby recovering the carrier wave, wherein, to this end, a complex sine wave whose central frequency is 1/n the symbol frequency is multiplied to generate a real component and imaginary Offset Quadrature Amplitude Modulation (OQAM) signals to calculate a phase error value from the real and imaginary component OQAM signals, to generate a complex sine wave compensating the calculated phase error value, to multiply the complex sine wave by the complex signal outputted from the phase splitter and to convert the complex signal to a baseband signal whose frequency offset is corrected.

Abstract: A method of transmitting a broadcast signal in a transmitter includes transmitting a transmission frame including a plurality of slots during which data groups of mobile data are transmitted, the mobile data being encoded through a Reed-Solomon (RS) frame and each row of a payload of the RS frame including a transport packet of the mobile data.

Abstract: A digital broadcast system and a method of processing data disclose. A receiving system of the digital broadcast system may include a baseband processor, a management processor, and a presentation processor. The baseband processor receives broadcast signals including mobile service data and main service data. The mobile service data configures a RS frame, and the RS frame includes the mobile service data and at least one type of channel setting information on the mobile service data. The management processor decodes the RS frame to acquire the mobile service data and the at least one type of channel setting information on the mobile service data, then extracts position information of an SDP message. Herein, the SDP message includes Codec information for each component in the respective virtual channel from the channel setting information, thereby accessing the SDP message from the extracted position information and gathers SDP message information.

Abstract: A carrier recovery apparatus usable with a VSB receiver and a method thereof. The carrier recovery apparatus is capable of recovering a carrier even though a pilot signal may be corrupted due to multi-path characteristics of a channel. Accordingly, the carrier recovery apparatus performs a BECM (Band Edge Component Maximization) algorithm on upper and lower sidebands of a received signal to generate phase information therefrom. The phase information is combined in a combiner. Since the BECM algorithm is performed on the upper and lower sidebands, it is possible to execute the carrier recovery even through the upper sideband of a received signal may be corrupted. Therefore, the carrier recovery apparatus can prevent performance degradation of the VSB receiver caused by corruption in the pilot signal.

Abstract: Briefly, a method an apparatus and a wireless communication device are provided. The wireless communication device includes a receiver to receive complex sequences of symbols. The receiver includes an estimator to estimate one or more channel taps. The estimator includes a memory to store at least a portion of one or more calculated values of an estimation matrix and is capable to estimate the one or more channel taps based on a stored portion of calculated values of the estimation matrix.

Abstract: A modulation apparatus is disclosed that enables significant improvements in signal transmission rate in a limited frequency band as compared with conventional modulation schemes. The modulation apparatus has first and second frequency-increasing single side band (SSB) modulators. The modulators are configured to have respective carrier frequencies with a difference by a frequency corresponding to the symbol frequency (i.e. fundamental frequency of the input symbol). An adder combines a lower side band (LSB) signal obtained from the SSB modulator set for a higher carrier frequency, and an upper side band (USB) signal obtained from the SSB modulator set for a lower carrier frequency to obtain a modulation signal.

Abstract: Implementation of Fast Information Channel (FIC) signaling when Chunks of FIC information span more than one sub-Frame of an M/H Frame is described. FIC signaling is advanced further at the digital television (DTV) transmitters than originally proposed, thereby eliminating need for substantial amounts of delay memory for coded M/H data in receivers for such data. Each FIC-Chunk includes a bit indicating when it is not applicable only to M/H Frames yet to be received but is also applicable to an M/H Frame being currently received. This facilitates reception being more quickly established after a change in DTV channel selection. Transmission Parameter Channel (TPC) signaling pertaining to the M/H Frame being currently received continues to the conclusion of the M/H Frame, so the total number of M/H Groups in each M/H sub-Frame is signaled to facilitate de-interleaving of the FIC signaling. Code combining of FIC Chunks is described.

Abstract: A digital broadcast system and a method of processing data disclose. A receiving system of the digital broadcast system may include a baseband processor, a management processor, and a presentation processor. The baseband processor receives broadcast signals including mobile service data and main service data. The mobile service data configures a RS frame, and the RS frame includes the mobile service data and at least one type of channel setting information on the mobile service data. The management processor decodes the RS frame to acquire the mobile service data and the at least one type of channel setting information on the mobile service data, then extracts position information of an SDP message. Herein, the SDP message includes Codec information for each component in the respective virtual channel from the channel setting information, thereby accessing the SDP message from the extracted position information and gathers SDP message information.

Abstract: A digital broadcast system and a method of processing data disclose. A receiving system of the digital broadcast system may include a baseband processor, a management processor, and a presentation processor. The baseband processor receives broadcast signals including mobile service data and main service data. The mobile service data configures a RS frame, and the RS frame includes the mobile service data and at least one type of channel setting information on the mobile service data. The management processor decodes the RS frame to acquire the mobile service data and the at least one type of channel setting information on the mobile service data, then extracts position information of an SDP message. Herein, the SDP message includes Codec information for each component in the respective virtual channel from the channel setting information, thereby accessing the SDP message from the extracted position information and gathers SDP message information.

Abstract: An E8-VSB reception system, apparatus for generating data attribute and method thereof, and apparatus for channel encoding and method thereof are disclosed. In the present invention, E8-VSB data resulting from multiplexing a plurality of enhanced data encoded at different coding rates with main data is received. And, the main data and a plurality of the enhanced data are identified to be modulated from the received E8-VSB data. In particular, by generating M/E packet attribute information, enhanced packet attribute information, enhanced byte attribute information and E8-VSB symbol attribute information from the E8-VSB data attribute generating apparatus, the channel decoding apparatus can correctly identify to decode the main data, ½ enhanced data and ¼ enhanced data from one another.

Abstract: A digital broadcasting transmission system processes dual transport stream (TS) including multi turbo streams. The digital broadcasting transmission system includes a turbo processor to detect a turbo stream from a dual transport stream (TS) which includes a multiplexed normal stream and a turbo stream, encoding the detected turbo stream and stuffing the encoded turbo stream into the dual TS; and a transmitter to trellis-encode the processed dual TS, and to output the resultant stream, wherein the turbo processor encodes the turbo stream using a plurality of turbo processors. Accordingly, a plurality of turbo streams may be processed in parallel.

Abstract: Methods of recovering symbols and corresponding communication receivers including dual receivers configured to perform the method, where the method comprises: sampling a received signal that includes interference to provide received samples; determining a plurality of high power symbols and determining alternate symbols for a portion of the plurality of high power symbols based on the received samples and based on known training symbols; and deriving a sequence of recovered symbols corresponding to the received samples based on the received samples and augmented training symbols, the augmented training symbols comprising the known training symbols augmented by the plurality of high power symbols with one or more alternate symbols replacing a corresponding one or more high power symbols.

Abstract: A method and a device for synchronizing the carrier frequency of a carrier signal comprising a frequency offset and/or a phase offset. According to the invention, the method estimates the frequency offset and/or phase offset of the carrier signal by means of a maximum likelihood estimation from a received signal, which comprises temporally discrete, complex rotary indices, for which only the temporally discrete phases are dependent on the frequency offset and/or phase offset. An offset quadrature-modulated received signal is thus converted into a modified received signal comprising temporally discrete, complex rotary indices, for which only the temporally discrete phases are dependent on the frequency offset and/or the phase offset.

Abstract: A method for receiving a broadcasting signal and a broadcasting signal receiver are disclosed. Even when a cell is changed while an emergency alert is output, the emergency alert can be continuously output using emergency alert table information included in the broadcasting signal and channel information of the cell. The emergency alert table information may include a cell identifier and the channel information of the cell may include virtual channel information of the cell.

Abstract: An echo cancellation reference signal is generated within a DTV transmitter by approximating a pair of successive repetitive PN sequences with 8VSB symbols arranged in sequences that are capable of being generated by ? trellis coding. The trellis coding is controlled so that the two sequences of 8VSB symbols can be linearly combined to generate a repetitive PN sequence doubled in amplitude and superposed on a constant-value pedestal. After this linear combining is performed by a comb filter in a DTV receiver, the resulting signal is convolved with the PN sequence as known a priori at the DTV receiver. This is a correlation procedure which generates the impulse response of the channel through which the DTV signal was received. The channel impulse response (CIR) provides a basis for computing the weighting coefficients of adaptive channel-equalization filtering in the DTV receiver.

Abstract: At the transmitter side, carrier waves are modulated according to an input signal for producing relevant signal points in a signal space diagram. The input signal is divided into, two, first and second, data streams. The signal points are divided into signal point groups to which data of the first data stream are assigned. Also, data of the second data stream are assigned to the signal points of each signal point group. A difference in the transmission error rate between first and second data streams is developed by shifting the signal points to other positions in the space diagram expressed at least in the polar coordinate system. At the receiver side, the first and/or second data streams can be reconstructed from a received signal. In TV broadcast service, a TV signal is divided by a transmitter into low and high frequency band components which are designated as first and second data streams respectively.

Abstract: A DTV transmitter includes a pre-processor pre-processing enhanced data, a data formatter generating enhanced data packets including known data, a multiplexer multiplexing the enhanced data packets with main data packets, a data randomizer randomizing the multiplexed data packets, an RS encoder RS-encoding the randomized data packets, and a data interleaver interleaving the RS-coded data packets, where a plurality of known data sequences are included in the interleaved enhanced data packets. Finally, the DTV transmitter further includes an enhanced encoder which codes each block of enhanced data placed between any two of the known data sequences and bypasses the interleaved main data packets.

Abstract: An enhanced VSB receiver includes a tuner which tunes an RF signal and converts it into an IF signal, an IF mixer which converts the IF signal into a baseband signal, and a demodulator which demodulates the baseband signal into a VSB signal. The enhanced VSB receiver further includes a map recovery unit which recovers VSB map information of the VSB signal, an enhanced equalizer for compensating channel distortion of the VSB signal and outputting an equalized symbol, and an enhanced Viterbi decoder for estimating whether polarity inversion occurred during a symbol period of the equalized symbol and Viterbi-decoding the equalized symbol based on the polarity estimation.