Abstract: A system and method for transmitting advanced television signals such as digital television signals. The system and method controls the frequency of the RF signal by compensating for errors in the signal received from a transport system. The system and method also reduces the complexity of the transmission system by inserting a pilot frequency signal after the television signal has been filtered and shaped.

Abstract: A system and method for controlling the frequency of a signal being transmitted wherein the frequency of the signal received at the transmitter site is error corrected before being broadcast. The error in the frequency may be developed and applied to the intermediate frequency upconversion and/or the channel upconversion to reduce or eliminate the effects of the error. In the system and method, a pilot frequency signal can be added to the signal to be broadcast after the signal to be broadcast has been shaped and filtered.

Abstract: A system and method for encoding via a trellis encoding scheme a digital data stream. The system and method finds particular application in the trellis encoding scheme used in the Grand Alliance digital television specification. In the system and method, a series of registers is used to cycle the digital bytes (or words) currently being interleaved and trellis encoded. A multiplexer selects the appropriate nibble of the data words for encoding during each cycle of the registers.

Abstract: An exciter for advanced television signals such as a digital television signal. The exciter corrects for instabilities in the television signal provided to it so as to produce a signal with tightly controlled frequency and reduced co-channel interference. The exciter inserts a pilot frequency into the digital television signal after the signal has been shaped, thereby reducing the difficulties of shaping. Also disclosed is a rate converter for use in an exciter so that a digital signal can be received at a first frequency and can be output at a second frequency in a manner in which the output of a signal is assured even in the absence of an input signal.

Abstract: A system and method for obtaining and maintaining synchronization to a digital signal containing framing. The method searches for a synchronizing pattern and maintains a confidence counter indicative of the success in finding the synchronization pattern where expected. The confidence counter can be used to indicate when the system is locked to the framing of the digital signal and when resynchronization needs to occur.