Abstract: A digital television (DTV) transmitter and a method of processing data in the DTV transmitter/receiver are disclosed. In the DTV transmitter, a pre-processor pre-processes the enhanced data by coding the enhanced data for forward error correction (FEC) and expanding the FEC-coded data. A packet formatter generates one or more groups of enhanced data packets, each enhanced data packet including the pre-processed enhanced data and known data, wherein the data formatter adds burst time information into each group of enhanced data packets. And, a packet multiplexer generates at least one burst of enhanced data by multiplexing the one or more groups of enhanced data packets with at least one main data packet including the main data, each burst of enhanced data including at least one group of enhanced data packets.

Abstract: Methods and apparatus are provided for reduced complexity Soft-Output Viterbi detection. A Soft-Output Viterbi algorithm processes a signal by determining branch metrics using a branch metrics unit; determining survivor paths for sequence detection using a first add-compare select unit; and determining survivor paths for generating one or more bit reliability values using a second add-compare select unit, wherein the first and second add-compare select units process the branch metrics determined by the branch metrics unit. The first and second add-compare select units can optionally process branch metrics having a different number of bits.

Abstract: Various embodiments implement distributed block coding (DBC). DBC can be used for, among other things, distributed forward error correction (DFEC) of source data in communication systems or parity backup for error correction of source data in storage systems where the source data may be corrupted by burst errors. A distributed block encoder (DBE) encodes sequential source data symbols with a plurality of sequential block encoders to produce interleaved parity codewords. The interleaved parity codewords enable decoding of error-corrected source data symbols with a distributed block decoder (DBD) that utilizes a plurality of sequential block decoders to produce the error-corrected source data symbols. A distributed register block encoder (DRBE) and a distributed register block decoder (DRBD) can each be implemented in a single block encoder and a single block decoder, respectively, by using a distributed register arrangement.

Abstract: A trellis decoder decodes a stream of encoded symbols, including symbols of a first type (e.g. symbols encoded with a first trellis code) and symbols of a second type (e.g. encoded with a second, more robust, trellis code), without storing path indicators along a trellis for symbols of the first type. In this way, limited memory may be used to store path indicators along the trellis for symbols of the second type. This allows for more accurate decoding of the symbols of the second type. For transitions from symbols of the second type to symbols of the first type, states of the trellis decoder may be stored. In this way, paths may be traced back along the trellis for trellis decoding, without the path indicators for the symbols of the first type.

Abstract: A channel equalizer includes a channel estimator, a coefficient calculator, a multiplier, and an error remover. The channel estimator estimates a channel impulse response (CIR) of input data in which a known data sequence is periodically inserted. The coefficient calculator calculates equalization coefficients using estimated CIR, and the multiplier multiplies the input data with the equalization coefficients for channel equalization. The error removes estimates a residual carrier phase error of the channel-equalized input data and removes the estimated phase error from the input data.

Abstract: Data to be more robustly transmitted within 8VSB broadcast DTV signals are turbo coded using parallelly concatenated convolutional coding (PCCC) and incorporated within the segments of data fields, the bytes of which are convolutionally interleaved before trellis coding and 8VSB symbol mapping. Packing the PCCC into payload fields of MPEG-2-compatible null data packets and Reed-Solomon coding the packets to generate the segments of data fields, the bytes of which are convolutionally interleaved, conditions legacy DTV receivers to disregard PCCC components not useful to them. Transversal packing turbo-coded Reed-Solomon codewords into the payload fields of MPEG-2-compatible null data packets increases the capability of those turbo-coded Reed-Solomon codewords to overcome burst errors. Repeated transmissions of the transversally packed turbo-coded Reed-Solomon codewords in whole or in part allows them to overcome protracted deep fades encountered during mobile reception of 8VSB DTV signals.

Abstract: A digital broadcast system and a method of processing data are disclosed. The receiving system of the digital broadcast system includes a signal receiving unit, a first data processor, a second data processor, and an A/V decoder. The signal receiving unit receives at least one of first mobile service data that is transmitted according to a first transmission method and second mobile service data that is transmitted according to a second transmission method. The first data processor performs demodulation on the first mobile service data received by the signal receiving unit using a first demodulation method and corrects errors occurring in the demodulated first mobile service data. The second data processor performs demodulation on the second mobile service data received by the signal receiving unit using a second demodulation method and corrects errors occurring in the demodulated second mobile service data.

Abstract: A modulation apparatus includes: a modulation section that modulates, in accordance with a correlation table where a data sequence with a predetermined number of bits is associated with a code sequence with a predetermined number of bits, the data sequence into the code sequence to allow a predetermined demodulation section to demodulate the code sequence into the data sequence in accordance with the correlation table, wherein the code sequence is, on NRZI method, a MSN code sequence where a null point of a frequency spectrum on a recording channel or communication channel of the code sequence is matched with a null point of a frequency spectrum of a PR equalized signal including the code sequence and a minimum run length is limited to be greater or equal to one.

Abstract: Apparatus and methods are disclosed for decoding data stored on a data storage medium. A disclosed decoding method and decoder include a radial incoherence (RI) detector that increases the probability of detecting RI and improves the decoding performance in terms of the bit error rate of the decoded signal. RI is detected by comparing an input signal to the decoder against a RI threshold value and generating a RI-type signal. The RI detector may include a filter for filtering out noise and error in the RI-type signal, an adaptive threshold unit that adjusts the RI threshold value based upon the RI-type signal, a transition-based threshold unit that adjusts the RI threshold value based upon each transition in the input signal, or a path-based threshold unit that adjusts the RI threshold value based upon a best surviving path corresponding to the input signal, in combination or alone.

Abstract: Apparatus and methods store error recovery data in different dimensions of a memory array. For example, in one dimension, block error correction codes (ECC) are used, and in another dimension, supplemental error correction codes, such as convolutional codes, are used. By using separate dimensions, the likelihood that a defect affects both error recovery techniques is lessened, thereby increasing the probability that error recovery can be performed successfully. In one example, block error correction codes are used for data stored along rows, and this data is stored in one level of multiple-level cells of the array. Supplemental error correction codes are used for data stored along columns, such as along the cells of a string, and the supplemental error correction codes are stored in a different level than the error correction codes.

Abstract: A Turbo decoder and method for decoding a double-binary circular recursive systematic convolutional (DBCRSC) encoded signal with unknown initial and final states executes iterations of forward and backward recursion on a payload block of the DBCRSC encoded signal and a padded block using an estimated forward state metric (FSM) and an estimated backward state metric (BSM), which are updated at one or more iterations.

Abstract: Provided are a method of estimating an encoder for dual stream transmission, and an encoder using the same. The method includes the steps of: a) setting up the number of memories required for an encoder, a free distance condition for robust data, and a free distance condition for mixed stream of robust data and normal data; b) obtaining ½ rate encoder combinations that sustain backward compatibility with a typical trellis encoder; c) obtaining encoder combinations H that satisfy the free distance condition for the robust data and the free distance condition for the mixed stream from the ½ rate encoder combinations; d) obtaining relations between memories and input/output signals, which satisfy the encoder combinations H; and e) configuring an encoder according to the obtained relation between the memories and the input/output signals.

Abstract: The disclosed technology provides systems and methods for identifying potential error locations, patterns, and likelihood metrics in connection with trellis-based detection/decoding. In one aspect of the invention, the disclosed technology computes soft reliability information for each detected/decoded bit or codeword syndrome value.

Abstract: Systems and methods for processing and decoding TCM/BCM-coded signal vectors. A multi-dimensional signal vector is received by, for example, a TCM or BCM decoder. The TCM/BCM decoder identifies the closest signal points in the signal constellation set, or “nearest neighbors,” for each dimension of the received signal vector. The TCM/BCM decoder then forms a test set that includes a plurality of multi-dimensional test vectors, where each dimension of each test vector is based on an identified nearest neighbor. In particular, each test point in the test set is based on a different combination of the nearest neighbors. The TCM/BCM decoder can compute branch metrics based on only the test points in the test set, and can make detection decisions using the computed branch metrics.

Abstract: A broadcast transmitting system and a method of processing broadcast data in the broadcast transmitting system are disclosed. Herein, the broadcast transmitting system includes a block processor for encoding mobile service data at a coding rate of 1/H, a group formatter for mapping the encoded mobile service data into at least one region of a data group that has a plurality of regions, wherein the data group further includes a plurality of known data sequences, a trellis encoder for trellis encoding data being outputted from the group formatter, the trellis encoder having at least one memory that is initialized at a start of each known data sequence, a multiplexer for multiplexing the trellis-encoded data with segment synchronization data and field synchronization data, and a modulator for modulating a broadcast signal including the multiplexed data.

Abstract: The metrics matrix may include at least one particular layer including at least one particular column having several metrics cues, respectively, situated in different rows. For the particular layer, the updating of the channel cue is associated with the particular column involving at each iteration one updated metric cue selected from all the metrics cues of the particular column. The row of the selected metric cues may change at each iteration.

Abstract: A universal method of trellis encoding signals mapped according to any signal constellation format involves constructing an encoder output table and a state transition table. The encoder output table defines the output symbol of an encoder given the input symbol and the present state of the encoder, while the state transition table defines the next state of the encoder given the present state of the encoder and the input applied to the encoder. The output table and the next state table are constructed with the objective of providing maximal distances between the branches of the trellis diagram without any regards for the shift register implementation of the code. Cyclic trellis-coded modulation is an example of such codes without feed-forward or feed-back shift register implementations, and with equal or better performance than “optimal” shift register trellis codes with 16 states or less.

Abstract: A method for implementation of error correction decoding of quadrature layered modulation QLM communications. A bound on communications capacity derived using ideal QLM is approximated with QLM communications links which support data rates independent of the Shannon bound. Trellis symbol and bit demodulation algorithms recover QLM data symbols and bit algorithms offer computational efficiency at a cost of decisioning errors. Correlated bit decisioning error correction decoding and re-encoding can be implemented in a bit demodulation algorithm. Trellis demodulation and trellis decoding algorithms support parallel implementations, and concatenated implementations wherein the error correction decoding is implemented after the QLM demodulation. Concatenated implementation supports turbo decoding, MAP decoding, convolutional decoding, and block decoding by using the decisioning metrics available from QLM demodulation in place of generating the decisioning metrics directly from the detected symbol measurements.

Abstract: Super block error correction code (ECC) adaptable to communication systems including hard disk drives (HDDs) and other memory storage devices. A means is presented by which a number of blocks of information can be organized, with a degree of ECC provided thereto, and transmitted via a signal into a communication channel. In some instances, the communication channel is coupled to a storage media as in the context of an HDD, and information is written to and read from the storage media via this communication channel (e.g., “read channel”). This means is particularly well suited to applications that provide large amounts of data via any one transmission (e.g., DVR/PVR (Digital/Personal Video Recorder)). A redundant block is generated using the information of each of a number of information blocks thereby provided extra ECC on a large portion of data, and that redundant block also undergoes ECC encoding.

Abstract: A system having a transmission unit transmitting an output data signal formed from output data and related error detection code and a corresponding receiving unit. The output data signal is pre-emphasized by a pre-emphasis driver in the transmission unit. The receiving unit includes an equalizer equalizing the received output data signal and an error detector analyzing the error detection code to determine whether a bit error is present in the received data. Upon successive data transmission failures either an equalization coefficient in the equalizer or a pre-emphasis coefficient in the pre-emphasis driver are changed.

Abstract: The present invention provides a novel technique for improving the performance of equalizers by reducing the effects of error propagation in equalizers that use a Viterbi Decoder. Methods and systems are described that can improve the performance of equalizers by reducing the effects of error propagation in equalizers that use a Viterbi Decoder. Systems and methods of symbol correction in prediction decision feedback equalization (“pDFE”) architectures are described. Systems are described that include one or more enhanced Viterbi decoders together with novel methods of symbol correction to obtain better system performance. Systems and methods are described that utilize dual pDFEs and can use a blending algorithm to reduce errors in symbol decoding. Dual pDFEs are described that include forward and backward Viterbi decoders wherein the backward Viterbi decoded may operate on time reversed data blocks and with some degree of latency.

Abstract: A trellis encoding device includes a plurality of trellis encoders to perform trellis-encoding of a transport stream into which a supplementary reference signal (SRS) has been inserted, and performs a memory reset in a region that precedes an SRS; and a parity compensation unit to compensate for parities of the transport stream in accordance with values stored in memories included in the trellis encoders. The plurality of trellis encoders may be implemented in diverse types. The trellis encoding device can perform a memory reset selectively using the stored value of the memory and the inverted value thereof, or selectively using the stored value of the memory and a fixed value. By properly resetting the memory in processing the transport stream into which the SRS has been inserted, DC offset can be reduced.

Abstract: Digital signals are transmitted on a bus at given instants selectively in a non-encoded format and an encoded format. The decision whether to transmit the signals in non-encoded format or in encoded format is taken in part, based on a comparison of the signal to be transmitted on the bus for an instant of the aforesaid given instants with the signal transmitter on the bus for the preceding instant, so as to minimize switching activity on the bus.

Abstract: Provided is a method, apparatus and computer program product for detecting a transport format of a multiplexed transport channel used for transferring binary data. A path metric value is determined, which estimates likelihood for a hypothetical trellis path to end at a predetermined state, for every state of a trellis stage of a possible end bit position of a data block of the transport channel. Then, for each possible end bit position a number of path metric values which indicate higher likelihood for the hypothetical trellis path to end at said predetermined state than an initial state is calculated, and the best end bit positions which lead to highest values of the calculated number are selected and error checking is performed for the selected best end bit positions to detect the transport format. The proposed selection of best end bit positions leads to a reduced number of decoding operations.

Abstract: In one embodiment, systems and methods of operating a SOVA system is disclosed that comprises determining the start and stop values for a trellis tree and using the start and stop values to determine the initial states of a plurality of branches within the trellis tree.

Abstract: System and methods for reducing the complexity or area of a non-linear Viterbi detector. In some embodiments, a Viterbi detector calculates branch metrics for a subset of the branches in a trellis diagram. This subset may be selected based on comparing an equalized signal with a signal level table of all the possible branches. These branch metrics may be calculated using high performance branch metric calculation techniques. The remaining branch metrics may be calculated based on the computed branch metrics using a technique that consumes fewer resources. The Viterbi detectors in the present invention may also be used in an iterative decoding scheme, where multiple detectors are cascaded. In these embodiments, a Viterbi detector may select a subset of the branches based on detection results from other Viterbi detectors.

Abstract: A digital television (DTV) transmitter/receiver and a method of processing data in the DTV transmitter/receiver are disclosed. In the DTV transmitter, a pre-processor pre-processes the 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 inserts known data to at least one of the enhanced data packets. A first multiplexer multiplexes the enhanced data packets with main data packets including the main data. And, an RS encoder RS-codes the multiplexed main and enhanced data packets, the RS encoder adding systematic parity data to each main data packet and adding RS parity plate holders to each enhanced data packet. Herein, the RS encoder may insert non-systematic RS parity data or null data into the RS parity place holders included in each enhanced data packet.

Abstract: An extensive use of look-up table (LUT) and single instruction multiple data (SIMD) in different algorithms in a software-defined radio (SDR) system is described. In particular, the LUT is used during spreading modulation, mapping and spreading, scrambling, de-scrambling, soft demapping, and the like. The SIMD is executed by a multi-core processor during implementation of a “min” operation to find an optimal path in a Trellis diagram for a Viterbi decoder.

Abstract: Various embodiments implement distributed block coding (DBC). DBC can be used for, among other things, distributed forward error correction (DFEC) of source data in communication systems or parity backup for error correction of source data in storage systems where the source data may be corrupted by burst errors. A distributed block encoder (DBE) encodes sequential source data symbols with a plurality of sequential block encoders to produce interleaved parity codewords. The interleaved parity codewords enable decoding of error-corrected source data symbols with a distributed block decoder (DBD) that utilizes a plurality of sequential block decoders to produce the error-corrected source data symbols. A distributed register block encoder (DRBE) and a distributed register block decoder (DRBD) can each be implemented in a single block encoder and a single block decoder, respectively, by using a distributed register arrangement.

Abstract: A digital broadcasting system and a data processing method are disclosed. The method includes receiving a data processing method includes receiving a broadcast signal in which main service data and mobile service data are multiplexed, acquiring transmission-parameter-channel signaling information including transmission parameter information of the mobile service data, and fast-information-channel signaling information, acquiring binding information describing a relationship between at least one ensemble transferring the mobile service data and a first virtual channel contained in the at least one ensemble by decoding the fast-information-channel, and acquiring status information of the first virtual channel, displaying content data contained in the mobile service data according to the binding information and the status information of the first virtual channel.

Abstract: Methods and systems are disclosed for decoding digital data received by a correspondent device over a communication channel. The data includes a component corresponding to a plurality of values unknown to the correspondent device and a component corresponding to one or more values known a priori by the correspondent device. To perform decoding, the correspondent device retrieves from memory at least one of the one or more known values. The correspondent device then applies a statistical measure using the known value(s) to estimate the location of the component corresponding to the one or more known values. The one or more known values and the estimated location of the component corresponding to the one or more known values are then used to assist in decoding the data.

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: A reliability unit is provided for determining a reliability value for at least one bit decision. The disclosed reliability unit comprises one or more functional elements, wherein each of the functional elements comprises at least four functional units and at least two registers, wherein each functional unit comprises a comparator and a multiplexer, and wherein an output of the comparator and an equivalence bit control the multiplexer. Generally, the reliability unit determines a reliability value for a bit decision associated with a maximum-likelihood path through a multiple-step trellis.

Abstract: A method of decoding a signal that has been encoded by a tail-biting code based on at least one encoding parameter is disclosed. The at least one encoding parameter may be a trellis size or a quantity of aggregated encoding elements or a code rate. The method is suitable for use in a communication device and comprises receiving (510) the signal, performing (520) a first decoding attempt of the signal based on a first set of starting state metrics and a first encoding parameter hypothesis, the first decoding attempt resulting in a first set of ending state metrics. The method further comprises performing (520), if the first decoding attempt fails, a second decoding attempt of the signal based on a second set of starting state metrics based on the first set of ending state metrics and a second encoding parameter hypothesis different from the first encoding parameter hypothesis. Corresponding arrangement, communication device, and computer program product are also disclosed.

Abstract: A digital television transmitting system includes a pre-processor, a packet generator, an RS encoder, and a trellis encoder. The pre-processor pre-processes enhanced data by coding the enhanced data for first forward error correction (FEC) and expanding the FEC-coded enhanced data. The packet generator generates first and second enhanced data packets including the pre-processed enhanced data and main data packets and multiplexes the enhanced and main data packets. The first enhanced data packet includes an adaptation field including the pre-processed enhanced data and second enhanced data packet includes a payload region including the pre-processed enhanced data. The RS encoder performs RS encoding on the multiplexed data packets for second forward error correction (FEC), and the trellis encoder performs trellis encoding on the RS-coded data packets.

Abstract: A method for recovering transmission errors, comprising: receiving a data packet (50) comprising an error detection code (51) associated to data contained in the packet, wherein the data associated to the error detection code comprises primary data (52) and secondary data (53), checking the error detection code of the received packet to detect an erroneous state of the associated data, when the erroneous state is detected, (86) determining a finite set of candidate values for the primary data and, for each candidate values of the set: determining a marginal likelihood of the candidate value as a function of the error detection code of the received packet, determining a first correlation between the primary data of the received packet and the candidate value, and selecting a corrected value for the primary data among the set of candidate values as a function of said marginal likelihoods and said first correlations.

Abstract: Described herein are one or more implementations of a high-throughput and memory-efficient “windowed” bidirectional Soft Output Viterbi Algorithm (BI-SOVA) decoder. The described BI-SOVA decoder uses the “window” technique to concurrently decode several different non-overlapping portions of a subject signal in parallel.

Abstract: A Viterbi decoding system interprets bits in received QAM constellations as many-valued parameters rather than binary valued parameters. It performs the Viterbi algorithm using these many-valued parameters to provide results superior to hard decision decoding. Rather than applying a hard 0-1 function to the QAM data, the system uses a non-stepped linear or curved transfer function to assign values to the bits. In another aspect, a system differentiates between data bits based on their estimated reliability, giving more emphasis to decoding reliable bits than unreliable bits using any of a variety of techniques. By differentiating between good and bad bits and de-emphasizing or ignoring unreliable bits, the system can provide a significant reduction in uncorrectable errors and packet loss.

Abstract: Systems and modules for use in trellis-based decoding of encoded sets of data bits. A memory system has multiple arrays for storing an index for each one of multiple states. With each array element being associated with a state through which a decoding path may pass through, the contents of each array element is an index which points to an immediately preceding state. This immediately preceding state is represented by another array element in another array. Each array is populated with array element entries as encoded data set are received by a separate decoder which generates the indices. For every given number of arrays in a group, a trace-back process traces back the path followed by an encoding procedure for encoding the encoded set. By tracing back this path through the various arrays, the original unencoded set of data bits can be found.

Abstract: A digital broadcast receiving system and a method for controlling the same are disclosed. The method a method for controlling a digital broadcast receiving system includes the steps of receiving a broadcast signal having mobile service data and main service data multiplexed therein, extracting transmission parameter channel (TPC) signaling information and fast information channel (FIC) signaling information from a data group within the received mobile service data, acquiring a program table, by using the IP signaling channel within an ensemble included in the received broadcast signal, and controlling the system to create a list of channels mapped with all ensembles transmitted through at least one physical frequency, by using the acquired program table.

Abstract: The present invention concerns a sphere decoder for maximum likelihood receiver intended to receive M-PPM-M?-PAM symbols at M modulation positions and at M? amplitude levels from a plurality P of sources. The sphere decoder uses a Schnorr-Euchner type enumeration adapted to classify the points of a multidimensional PPM-PAM modulation.

Abstract: A baseband processing module for use within a Radio Frequency (RF) transceiver includes a downlink/uplink interface, TX processing components, a processor, memory, RX processing components, and a turbo decoding module. The RX processing components receive a baseband RX signal from the RF front end, produce a set of IR samples from the baseband RX signal, and transfer the set of IR samples to the memory. The turbo decoding module receives a set of IR samples from the memory, forms a turbo code word from the set of IR samples, turbo decodes the turbo code word to produce inbound data, and outputs the inbound data to the downlink/uplink interface. The turbo decoding module performs metric normalization based upon a chosen metric, performs de-rate matching on the set of IR samples, performs error detection operations, and extracts information from a MAC packet that it produces.

Abstract: A method for developing a circuit is disclosed. The method generally comprises the steps of (A) generating a solution space having a dimension for each of a plurality of parameters for the circuit, (B) evaluating a plurality of instances of the circuit in the solution space through a software simulation, (C) evaluating the instances through a hardware simulation, and (D) updating the instances in response to the software simulation and the hardware simulation to approach an optimum instance of the instances for the circuit.

Abstract: A vestigial sideband (VSB) modulation transmission system and a method for encoding an input signal in the system are disclosed. According to the present invention, the VSB transmission system includes a convolutional encoder for encoding an input signal, a trellis-coded modulation (TCM) encoder for encoding the convolutionally encoded signal, and a signal mapper mapping the trellis-coded signal to generate a corresponding output signal. Different types of the convolutional encoders are explored, and the experimental results showing the performances of the VSB systems incorporating each type of encoders reveals that a reliable data transmission can be achieved even at a lower input signal to noise ratio when a convolutional encoder is used as an error-correcting encoder in a VSB system.

Abstract: A digital broadcasting system and a data processing method are disclosed. The method includes receiving a data processing method includes receiving a broadcast signal in which main service data and mobile service data are multiplexed, acquiring transmission-parameter-channel signaling information including transmission parameter information of the mobile service data, and fast-information-channel signaling information, acquiring binding information describing a relationship between at least one ensemble transferring the mobile service data and a first virtual channel contained in the at least one ensemble by decoding the fast-information-channel, and acquiring status information of the first virtual channel, displaying content data contained in the mobile service data according to the binding information and the status information of the first virtual channel.

Abstract: Teachings presented herein offer reduced computational complexity for symbol sequence estimation, and also provide for the generation of soft bit values representing the reliability of that estimation. A demodulator is configured to generate these soft bit values by identifying a candidate value for each symbol in the sequence which is more likely than at least one other in a defined set of candidate values. Based on the candidate value identified for each symbol, the demodulator forms a reduced set of candidate values for the symbol by selecting as many additional candidate values from the defined set as are needed to have complementary bit values for each bit value in that identified candidate value. The demodulator calculates soft bit values for the symbol sequence based on a sequence estimation process whose state space for each symbol is constrained to the corresponding reduced set.

Abstract: A method for calculating backward state metrics of a trellis, the method includes: performing a radix-K calculation of backward state matrices of multiple states of at least one time instance of a trellis; and performing a radix-J calculation of backward state matrices of multiple states of at least one other time instance of the trellis; wherein K differs from J.

Abstract: A method for generating soft bit values for a multi-bit symbol encoded in one or more received signals comprises (a) for a plurality of different combinations of multiple bit values, iteratively generating, for each combination, a metric value based on the one or more received signals. The method further comprises (b) for each iteration, maintaining (i) a global extremum register containing a global extremum of the metric values; (ii) a bit occupancy for the global extremum register; and (iii) a plurality of bit bk registers, one for each bit bk in the symbol. Each bit bk register contains an extremum of the metric values corresponding to combinations of multiple bit values whose bit bk value is opposite the bit bk value of the bit occupancy for the global extremum register. The method further comprises (c) generating, for each bit bk in the symbol, a soft bit value based on a difference between the value in the global extremum register and the value in the corresponding bit bk register.

Abstract: A method of broadcasting an AM compatible digital audio broadcasting signal includes: producing an analog modulated carrier signal centrally positioned in a radio channel, wherein the analog modulated carrier signal is modulated by an analog signal, producing a plurality of digitally modulated subcarrier signals in the radio channel, wherein the digitally modulated subcarrier signals are modulated using complementary pattern-mapped trellis code modulation (CPTCM) including a code mapped to overlapping partitions including an upper main partition, a lower main partition, an upper backup partition and a lower backup partition, and a non-overlapping tertiary partition, and transmitting the analog modulated carrier signal and the plurality of digitally modulated subcarrier signals. Transmitters that broadcast the signal and receivers that receive the signal, and the reception method are also included.

Abstract: A data field of transmitted digital television signals includes a first set of A/53-compliant data segments that convey payload information and further includes a second set of A/53-compliant data segments that contain parity bytes for transverse Reed-Solomon forward-error-correction coding of the data contained within the first set of A/53-compliant data segments. A digital television receiver uses the parity bytes in the second set of A/53-compliant data segments to implement transverse Reed-Solomon forward-error-correction decoding that corrects byte errors in the data contained in the first set of A/53-compliant data segments.