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 receiver is an ATSC (Advanced Television Systems Committee)-receiver and comprises a controller and an equalizer, which comprises a feed-forward filter and a feed-back filter. The feed-forward filter comprising at least one tap associated with at least one tap coefficient value. The controller determines a location of at least one tap of the equalizer; and if that location is close to a tap boundary (or edge) of the equalizer, the at least one tap of the equalizer is shifted forward or backward by at least one sample position.
Abstract:
An apparatus and method for encoding a signal are provided. The apparatus and method of the present disclosure identify (404) the various portions, or bytes, of an incoming packet in a Reed-Solomon (RS) encoded packet as either data bytes, RS parity bytes, or trellis reset synchronization bytes. The data bytes are passed through without change. The trellis reset bytes are provided to a trellis encoder to determine new byte reset values (406). These new values are then stored (408) and later retrieved (410) when needed and used to modify the appropriate incoming parity bytes. The new incoming parity bytes are computed (412) using the new trellis reset byte values multiplied by, or added to, a weighting value retrieved from a table stored in memory based on a location of the parity byte and a location of the trellis reset byte in the RS encoded packet.
Abstract:
A receiver is an ATSC (Advanced Television Systems Committee)-receiver and comprises a staggered quadrature amplitude modulator for providing an staggered quadrature amplitude modulated (SQAM) signal from a received signal; a data-aided carrier tracking loop (CTL) and a data-aided symbol timing recovery (STR) loop. The data-aided CTL operates such that the data-aided CTL is now insensitive to timing phase offset.
Abstract:
Communications systems often use networks including separately located transmitters and exciters for signal transmission as part of a single frequency network. A method is described that includes receiving (610) a broadcast signal stream containing a data packet and a synchronization timing packet, the synchronization timing packet containing signal transmission delay parameters provided to at least two transmitters, identifying (630) a synchronization interval in the broadcast signal stream, and determining (640) a transmission time for the data packet in the broadcast signal stream based on the signal transmission delay parameters and a time position of the packet with respect to the synchronization interval. An apparatus includes a multiplexer (110) that generates a transport stream containing a data packet and a synchronization timing packet, an exciter (118a-n), that identifies a synchronization interval in the broadcast signal stream and an antenna (120a-n), transmits a broadcast signal based on the synchronization timing packet and the synchronization interval.
Abstract:
The determination and identification of channels in a signal is an important aspect of the operation of a signal receiver. A method (800) is described including the steps receiving (802) a signal containing a plurality of channels, filtering (806) the signal to produce an indicator of a channel band edge, and determining (818) a characteristic of the channel based on the indicator. Additionally, an apparatus (300) is described including a spectrum shift circuit (304) that receives an input signal and shifts the frequency spectrum of the signal, a filter (306) that filters the frequency shifted signal to produce an indicator of a band edge of a channel, and a signal analysis circuit (316, 318) that determines a characteristic of the channel based on the indicator of the band edge, the signal analysis circuit (316, 318) controlling the frequency shift in the spectrum shift circuit (304) based on the determined characteristic of the channel.
Abstract:
A receiver is an ATSC (Advanced Television Systems Committee) -receiver and comprises a phase lock loop (PLL) for performing carrier tracking of a carrier in a received signal. The PLL includes a detector (160) comprising two pseudo-Hilbert filters (205, 215). The detector uses energy from both band edges of the received ATSC signal for driving the PLL.
Abstract:
Communications systems often use networks including separately located transmitters and exciters for signal transmission. An apparatus and method for synchronization of trellis states in a network are provided. The apparatus and method provide for generating a data stream including at least one training sequence (402), generating trellis initialization information based on the data stream (404), inserting the trellis initialization information into the data stream in a predetermined location (406). The present disclosure further provides for inserting in the data stream a packet for determining when to perform a trellis state reset. In certain embodiments, the packet includes a bit for determining when to selectively disable parity replacement of the data stream to synchronize trellis states across multiple exciters.
Abstract:
A receiver is an ATSC (Advanced Television Systems Committee)-receiver and comprises a staggered quadrature amplitude modulator for providing an staggered quadrature amplitude modulated (SQAM) signal from a received signal; an equalizer and a data-aided symbol timing recovery (STR) loop. The equalizer operates outside of the data-aided symbol timing recover loop.
Abstract:
A receiver is an ATSC (Advanced Television Systems Committee)-receiver and comprises a staggered quadrature amplitude modulator for providing an staggered quadrature amplitude modulated (SQAM) signal from a received signal; a data-aided carrier tracking loop (CTL) and a data-aided symbol timing recovery (STR) loop. The data-aided STR loop operates such that the data-aided STR loop is now insensitive to carrier phase offset.