Abstract: Mobile/handheld (M/H) data is received in an M/H frame equivalent in size to exactly 20 VSB data frames. Each VSB frame contains an odd VSB field and an even VSB field, and each of the VSB fields includes one field sync segment and 312 data segments. The M/H frame includes main data and M/H data, and the M/H data has more robust coding than the main data. The M/H frame is received and an MPEG encoded transport stream derived therefrom is outputted. Frame registration is found so as to find a structure of the M/H frame in the MPEG encoded transport stream. Based on the structure of the M/H frame, the M/H data is randomized. Based on the structure of the M/H frame, block mode data is located within the randomized M/H data. The M/H data is decoded using the block mode data.

Abstract: A repeater receives an input signal containing mobile/handheld (M/H) data received in an M/H frame equivalent in size to 20 VSB data frames. Each VSB frame contains an odd VSB field and an even VSB field, and each of the VSB fields includes one field sync segment and 312 data segments. The M/H frame includes main data and M/H data, and the M/H data has more robust coding than the main data. The received input signal is demodulated to produce an MPEG transport steam. Frame registration is used to find data and field syncs in the MPEG transport steam. The trellis encoder is reset prior to M/H training data in to the mobile data stream. The data is VSB modulated, the field syncs are added to the modulated data to reconstruct the M/H frame, and the M/H frame upconverted to an RF output signal, which is retransmitted.

Abstract: A repeater receives an input signal containing mobile/handheld (M/H) data received in an M/H frame equivalent in size to 20 VSB data frames. Each VSB frame contains an odd VSB field and an even VSB field, and each of the VSB fields includes one field sync segment and 312 data segments. The M/H frame includes main data and M/H data, and the M/H data has more robust coding than the main data. The input signal, is received and demodulated to produce an MPEG transport steam. Frame registration is found so as to find data and field syncs in the MPEG transport steam. The trellis encoder is reset prior to the M/H training data in to the mobile data stream. The data is VSB modulated, the field syncs are added to the modulated data to reconstruct the M/H frame, and the M/H frame upconverted to an RF output signal. The RF output signal is retransmitted.

Abstract: Mobile/handheld (M/H) data is received in an M/H frame equivalent in size to exactly 20 VSB data frames. Each VSB frame contains an odd VSB field and an even VSB field, and each of the VSB fields includes one field sync segment and 312 data segments. The M/H frame includes main data and M/H data, and the M/H data has more robust coding than the main data. The M/H frame is received and an MPEG encoded transport stream derived therefrom is outputted. Frame registration is found so as to find a structure of the M/H frame in the MPEG encoded transport stream. Based on the structure of the M/H frame, the M/H data is randomized. Based on the structure of the M/H frame, block mode data is located within the randomized M/H data. The M/H data is decoded using the block mode data.

Abstract: Program clock references in first and second MPEG data streams are re-stamped in accordance with delays introduced into the first and second MPEG data streams. Accordingly, the program clock references in the first MPEG data stream are re-stamped according to a variable delay in the first MPEG data stream, and the program clock references in the second MPEG data stream are re-stamped according to a variable delay in the second MPEG data stream. The re-stamped program clock references in the second MPEG data stream are corrected according to a fixed delay in the second MPEG data stream. The first and second MPEG data streams are multiplexed, and the multiplexed first and second MPEG data streams are transmitted and received.

Abstract: Program clock references in first and second MPEG data streams are re-stamped in accordance with delays introduced into the first and second MPEG data streams. Accordingly, the program clock references in the first MPEG data stream are re-stamped according to a variable delay in the first MPEG data stream, and the program clock references in the second MPEG data stream are re-stamped according to a variable delay in the second MPEG data stream. The re-stamped program clock references in the second MPEG data stream are corrected according to a fixed delay in the second MPEG data stream. The first and second MPEG data streams are multiplexed, and the multiplexed first and second MPEG data streams are transmitted and received.

Abstract: Audio packets occupy spaces in a packet stream so as to reduce packet jitter in a receiver.

Abstract: Program clock references in first and second MPEG data streams are re-stamped in accordance with delays introduced into the first and second MPEG data streams. Accordingly, the program clock references in the first MPEG data stream are re-stamped according to a variable delay in the first MPEG data stream, and the program clock references in the second MPEG data stream are re-stamped according to a variable delay in the second MPEG data stream. The re-stamped program clock references in the second MPEG data stream are corrected according to a fixed delay in the second MPEG data stream. The first and second MPEG data streams are multiplexed, and the multiplexed first and second MPEG data streams are transmitted and received.

Abstract: Program clock references in first and second MPEG data streams are re-stamped in accordance with delays introduced into the first and second MPEG data streams. Accordingly, the program clock references in the first MPEG data stream are re-stamped according to a variable delay in the first MPEG data stream, and the program clock references in the second MPEG data stream are re-stamped according to a variable delay in the second MPEG data stream. The re-stamped program clock references in the second MPEG data stream are corrected according to a fixed delay in the second MPEG data stream. The first and second MPEG data streams are multiplexed, and the multiplexed first and second MPEG data streams are transmitted and received.

Abstract: Program clock references in first and second MPEG data streams are re-stamped in accordance with delays introduced into the first and second MPEG data streams. Accordingly, the program clock references in the first MPEG data stream are re-stamped according to a variable delay in the first MPEG data stream, and the program clock references in the second MPEG data stream are re-stamped according to a variable delay in the second MPEG data stream. The re-stamped program clock references in the second MPEG data stream are corrected according to a fixed delay in the second MPEG data stream. The first and second MPEG data streams are multiplexed, and the multiplexed first and second MPEG data streams are transmitted and received.

Abstract: Audio packets occupy spaces in a packet stream so as to reduce packet jitter in a receiver.

Abstract: A synchronous data link signal is generated for supply between digital television equipment in a studio and an RF transmitter. The synchronous data link signal includes first data to be encoded at a first data rate, second data to be encoded at a second data rate less than the first data rate, and a map defining the relative amounts and placement of the encoded first and second data in the synchronous data link signal. The first data is in the form of first output data packets of a predetermined size. The second data and the map data are multiplexed so as to provide more than one second output data packet having the predetermined size. The first and second output data packets are then multiplexed so as to provide the synchronous data link signal.

Abstract: A field transmitted by a transmitter and received by a receiver has a map indicating the number of E-VSB segments and VSB segments in the field. The E-VSB segments contain E-VSB data, and the VSB segments contain VSB data. The VSB data includes video and/or audio data. The audio data in the field is limited to a predetermined data rate when the VSB data in the field has a VSB bit rate below a predetermined threshold. This limit reduces or eliminates audio related jitter in the receiver.

Abstract: A field contains a map, a number of E-VSB data segments, and a number of VSB data segments. The map indicates at least the number of E-VSB data segments in the field. The E-VSB data segments are located in the field such that the spacing between the E-VSB segments comprises only x and x+1, where x is dependent on the number of E-VSB data segments in the field as indicated by the map.

Abstract: A field contains a map, a number of E-VSB data segments, and a number of VSB data segments. The map indicates at least the number of E-VSB data segments in the field. The E-VSB data segments are located in the field such that the spacing between the E-VSB segments comprises only x and x+1, where x is dependent on the number of E-VSB data segments in the field as indicated by the map.

Abstract: A synchronous data link signal is generated for supply between digital television equipment in a studio and an RF transmitter. The synchronous data link signal includes first data to be encoded at a first data rate, second data to be encoded at a second data rate less than the first data rate, and a map defining the relative amounts and placement of the encoded first and second data in the synchronous data link signal. The first data is in the form of first output data packets of a predetermined size. The second data and the map data are multiplexed so as to provide more than one second output data packet having the predetermined size. The first and second output data packets are then multiplexed so as to provide the synchronous data link signal.

Abstract: VSB data is transmitted in a frame which includes a frame sync, a segment sync, a mode control, and a plurality of data symbols. The mode control indicates the number of modulation levels of the data symbols and includes 2-level symbols forming the following byte: PABCPABC. P is a parity bit, and ABC represents a selected one of a plurality of data constellations defining the modulation levels of the data symbols.

Abstract: A symbol sync acquisition circuit for a digital VSB signal finds sync pattern correlations in the incoming signal. Initially both positive and negative sync pattern correlations are accorded equal weight, with non sync pattern correlations being accorded a negative weight. Values are accumulated in a segment integrator and stored in a FIFO having a location for each symbol position in a segment. A comparator initially produces an output when sync pattern correlations are found that add to a given value. After a relatively small number of correlations, as tabulated in a confidence counter, a VCO is enabled to change its frequency under control of error pulses based upon the symbol sync. After a greater number of sync pattern correlations, the symbol position in the segment is fixed, sliding to a new symbol location in the FIFO is precluded, the signal polarity is determined and changed, if necessary, and a higher threshold is established for the comparator.

Abstract: A digital data processing system receives compressed variable length encoded digital data in the form of variable length codewords in contiguous variable speed Blocks of data. The boundary signals between adjacent codewords are determined and a demultiplexer sequentially sorts the serial digital data among a plurality of parallelly connected buffers for reducing the bit read speed of the buffers. A corresponding plurality of variable length decoders decodes the data from the buffers and outputs the data in parallel form to a multiplexer where it is reassembled into a serial expanded data stream. The incoming data includes selector information in fixed length headers that are separated, buffered and variable length decoded for controlling the demultiplexer. In one aspect of the invention, the data is sorted into substantially equal sized groups of integral codewords for equalizing the loading of the parallel buffers.

Abstract: A digital data processing system receives compressed variable length encoded digital data in the form of variable length codewords in contiguous variable speed Blocks of data. The boundary signals between adjacent codewords are determined and a demultiplexer sequentially sorts the serial digital data among a plurality of parallelly connected buffers for reducing the bit read speed of the buffers. A corresponding plurality of variable length decoders decodes the data from the buffers and outputs the data in parallel form to a multiplexer where it is reassembled into a serial expanded data stream. The incoming data includes selector information in fixed length headers that are separated, buffered and variable length decoded for controlling the demultiplexer. In one aspect of the invention, the data is sorted into substantially equal sized groups of integral codewords for equalizing the loading of the parallel buffers.