Abstract: Data to be more robustly transmitted within 8VSB broadcast DTV signals are turbo coded using parallel 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 television (DTV) system uses parallel concatenated coding (PCC), together with QAM constellations for modulating OFDM carriers. A first encoder responds to ONEs' complemented bits of randomized data to generate a first component of PCC. A second encoder responds to delayed bits of the randomized data to generate a second component of PCC. A constellation mapper generates QAM symbols responsive to successive time-slices of the first component of the PCC interleaved with successive time-slices of the second component of the PCC. An OFDM modulator generates a COFDM modulating signal responsive to the QAM symbols. In a receiver for the DTV system, the second component of the PCC and delayed first component of the PCC are iteratively decoded. Soft bits from the second component and delayed first component of the parallel concatenated coding are code-combined to supply soft randomized data used in that iterative decoding.

Abstract: A digital television (DTV) system uses parallel concatenated coding (PCC), together with QAM constellations for modulating OFDM carriers. A first encoder responds to bits of randomized data to generate a first component of parallel concatenated coding. A second encoder responds to delayed bits of the randomized data to generate a second component of parallel concatenated coding. A constellation mapper generates QAM symbols responsive to successive time-slices of the first component of the PCC interleaved with successive time-slices of the second component of the PCC. An OFDM modulator generates a COFDM modulating signal responsive to the QAM symbols. In a receiver for the DTV system, the second component of the PCC and delayed first component of the PCC are iteratively decoded. Corresponding soft bits from the second component and delayed first component of the PCC are combined to supply soft randomized data used in that iterative decoding.

Abstract: A receiver of COFDM digital television signals includes an inner decoder for iterative soft-decision decoding of concatenated convolutional coding (CCC) and an outer decoder for Reed-Solomon (RS) coding. The receiver generates error flags for identifying code symbols to be erased before the output symbols from the inner decoder are byte de-interleaved and supplied to the outer decoder. Generation of those flags depends on soft decoding results from the inner decoder. The method of locating errors ascribes to each byte supplied to the outer decoder for RS coding the highest lack-of-confidence level specified by the soft data bits associated with that byte. The method is described as being extended to locate byte errors in plural-dimension cross-interleaved Reed-Solomon codes (CIRC) apt to be employed in DTV broadcasting to mobile and handheld receivers.

Abstract: Receivers with capability for iterative-diversity reception of COFDM digital television transmissions of repeated similarly coded data are described. Also described are receivers with capabilities for receiving COFDM digital television transmissions in which earlier transmissions of coded data are later followed by subsequent transmissions of the same data differently coded. The receivers use maximal-ratio code combining techniques for repeated components in the COFDM digital television transmissions. The receivers use turbo decoding techniques for concatenated coding of data in the COFDM digital television transmissions.

Abstract: Digital television broadcasting signals employ parallel concatenated convolutional coding, commonly called “turbo coding”, to improve reception by receivers in motor vehicles. Turbo coded Reed-Solomon codewords are transversally disposed in the payload fields of encapsulating MPEG-2-compliant packets to improve the capability of the Reed-Solomon coding to overcome deep fades. Turbo codewords are transmitted more than once in so-called “staggercasting”. Reception of DTV signals is improved by combining soft decisions concerning repeated transmissions of turbo codewords before turbo decoding. Only the data components of turbo codewords are transmitted twice in “punctured” staggercasting of turbo codewords, with parity components being transmitted only once, so code rate is reduced by a smaller factor than two.

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 iterative-diversity (ID) transmission systems for signals with concatenated convolutional coding (CCC), paired iterative diversity signals each have ½ the code rate of the 8VSB DTV signals prescribed by the 1995 ATSC Digital Television Broadcast Standard. Known serial concatenated convolutional coding (SCCC) or novel parallel concatenated convolutional coding (PCCC) is used in such system. Pairs of CCC signals code data bits and ones' complemented data bits respectively, using similar coding algorithms. Receivers for this transmission system use respective turbo decoders for turbo decoding the earlier-transmitted and later-transmitted CCC signals. Turbo decoding of the earlier-transmitted portions of iterative diversity signals is delayed to be contemporaneous with turbo decoding of the later-transmitted portions of iterative diversity signals. This facilitates the turbo decoders exchanging information concerning confidence levels of data bits during the turbo decoding procedures.

Abstract: At least two turbo decoding apparatuses are used in a receiver for concatenated convolutional coding transmissions imbedded in 8-VSB digital television signals. This permits turbo decoding procedures for the M/H Groups in any Parade consisting of eight or fewer M/H Groups to be interleaved so at least one M/H Slot interval after each of those M/H Groups has been received is available for decoding that M/H Group.

Abstract: Digital television broadcasting signals employ parallel concatenated convolutional coding, commonly called “turbo coding”, to improve reception by receivers in motor vehicles. Turbo coded Reed-Solomon codewords are transversally disposed in the payload fields of encapsulating MPEG-2-compliant packets to improve the capability of the Reed-Solomon coding to overcome deep fades. Turbo codewords are transmitted more than once in so-called “staggercasting”. Reception of DTV signals is improved by combining soft decisions concerning repeated transmissions of turbo codewords before turbo decoding. Only the data components of turbo codewords are transmitted twice in “punctured” staggercasting of turbo codewords, with parity components being transmitted only once, so code rate is reduced by a smaller factor than two.

Abstract: 8VSB digital television signals employing serially concatenated convolutional coding (SCCC) are transmitted twice in an SCCC staggercasting procedure. In the receiver for such signal “soft” decisions concerning the initial and final transmissions are compared as a basis for synthesizing a set of “soft” decisions for implementing turbo decoding procedures. In a “punctured” variant of the SCCC staggercasting procedure, SCCC using one type of outer convolutional coding is transmitted at a relatively early time and after a prescribed interval SCCC using another type of outer convolutional coding of the same data is transmitted at a relatively late time. In the receiver for such signal “soft” decisions concerning data bits the initial and final transmissions are compared as a basis for synthesizing a set of “soft” decisions for implementing turbo decoding procedures.

Abstract: The outer convolutional coding of the signals used to transmit mobile-handheld (M/H) service data within digital-television (DTV) signals is subjected to anti-Gray coding, either before or after its interleaving, but before its inner convolutional coding. In a receiver for such M/H-service data, portions of the trellis decoded DTV signal containing soft decisions concerning symbol-interleaved convolutionally coded M/H-service data are recoded for a Gray-code mapping of symbols to modulation levels. This is done either before or after symbol de-interleaving, but before decoding the outer convolutional coding. Soft decisions concerning extrinsic information to be fed back to the ? trellis decoder to close a turbo decoding loop are derived from soft decisions as to the M/H-service data, which derivation includes re-coding for a binary-code mapping of symbols to modulation levels. Each re-coding procedure can be performed using ROM, but preferably is performed using simple digital logic.

Abstract: Modification of the prior-art M/H system to better suit transmission of internet-protocol (IP) transport packets includes a standard codeword length for a plurality of various options for transverse Reed-Solomon coding of M/H data, which options offer different degrees of forward-error-correction capability. A 235-byte standard codeword length for TRS coding of M/H data allows extending the FIC-Chunks in the Fast Information Channel signaling to double length so as to substantially increase the capability of such signaling to convey information concerning M/H services. In some transmitter apparatus constructed in accordance with aspect of the invention the TRS encoder in the M/H Frame encoder is modified for transmitting the parity bytes of TRS codewords before, rather than after, the data bytes of those TRS codewords.

Abstract: A radio receiver for receiving a selected digital HDTV signal, irrespective of whether it is a complex-amplitude-modulation (QAM) or a vestigial sideband (VSB) signal, using the same tuner. The tuner supplies a final IF signal in a 6 MHz frequency band, the lowest frequency of which is not appreciably more than 2.38 MHz. The final IF signal is digitized for synchrodyning to baseband, with the 2.375 MHz difference between the carrier frequencies of QAM and VSB signals being taken into account in the digital synchrodyning circuitry. The carrier frequencies of the QAM and VSB final IF signals are regulated to be submultiples of symbol frequency by applying automatic frequency and phase control signals developed in the digital circuitry to a local oscillator of the tuner. The presence of the pilot carrier accompanying a selected VSB HDTV signal is detected for automatically switching the radio receiver for operation in a VSB signal reception mode.

Abstract: Non-systematic (207, 187) Reed-Solomon codewords contain valuable information concerning the correctness of the outer convolutional coding of the serial concatenated convolutional coding, (SCCC) used for transmitting M/H-service data. An M/H receiver can decode the non-systematic (207, 187) Reed-Solomon coded MHE packets before and during turbo decoding of the SCCC. The decoding results are used to influence the soft decisions concerning bits of the SCCC that arise during SCCC decoding procedures. The decoding results can sometimes correct errors in the outer convolutional coding of the SCCC. The decoding results can be employed to stop the iterative SCCC decoding procedures sometimes before reaching a prescribed maximum number of iterations.

Abstract: A system for broadcasting the same data in concatenated convolutional coded (CCC) form from a network of 8-VSB amplitude-modulation transmitters operated with different radio-frequency carrier waves assigns the coded data to time-interleaved ones of time slots that are universal throughout the network. Therefore, a mobile/handheld (M/H) receiver with a single frequency-agile tuner can provide frequency-diversity reception of the time-interleaved data in CCC form. Alternatively, an M/H receiver with two tuners is used to provide frequency-diversity reception of the time-interleaved data in CCC form. The system for a network of 8-VSB AM transmitters that broadcast the same data in CCC form can further provide for each 8-VSB AM transmitter to make repeated transmissions of data in CCC form, to facilitate iterative-diversity reception of those transmissions by M/H receivers.

Abstract: Apparatus for transmitting digital data in an 8-vestigial sideband (8-VSB) signal format for reception by mobile/handheld (M/H) receivers is described. The apparatus for transmitting digital data includes a generator of MHE packet headers that include additional information about at least part of the digital data and a packet formatter that installs the MHE packet headers in the MHE packets. Apparatus for receiving the digital data and recovering the additional information from the MHE packet headers to be used for modifying operation of the receiving apparatus is also described.

Abstract: Electromagnetic signals for transmitting television and other information more robustly have amplitudes modulated in accordance with a digital signal generated by convolutional interleaving and trellis coding of segments of successive data fields, each of which segments contains a prescribed number of bytes. In improvements of these signals, respective fractional portions of a Reed-Solomon forward-error-correction codeword are transmitted in respective ones of a plurality of the segments of the successive data fields. The respective ones of the plurality of segments are separated from each other within the successive data fields, such that their individual bytes do not interleave with each other after the convolutional interleaving and trellis coding are completed.

Abstract: A DTV signal is transmitted that avoids legacy DTV receivers regarding data segments used in other than ordinary 8VSB transmissions being mistaken for (207, 187) R-S FEC codewords that appear to free of byte error or can be corrected to appear so. The DTV signal is analyzed prior to its transmission, for detecting those data segments used in other than ordinary 8VSB transmissions that legacy DTV receivers could mistake for correct (207, 187) R-S FEC codewords or correctable (207, 187) R-S FEC codewords. Twenty bytes of each segment of data that could be so mistaken are modified to prevent such mistake. Complementing certain bits in the final twenty bytes of each segment of data is preferred if data are transmitted at one-half or one-quarter ordinary 8VSB code rate. Segments of control data, each pertaining to a respective future group of said segments of data, are transmitted in a further aspect of the invention for indicating which data segments are modified.

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.