Abstract: A digital power level control is presented for an RF broadcast transmitter. This control includes an RF high power amplifier that receives an RF signal from an exciter and provides therefrom an amplified RF output. An adjustable attenuator is interposed between the exciter and the power amplifier for adjusting the level of the RF signal. An RF controller adjusts the attenuator. A high power amplifier controller controls the high power amplifier. A communication bus interconnects the controller.

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: The present invention provides an apparatus for providing error correction data in a digital data transfer system. The apparatus receives a clock signal and provides a first signal using the clock signal. Information data is received and a second signal is provided using the information data. The information data is received in groups which each have a first predetermined number of elements. A plurality of &agr;ROMs provide Galois Field multiples in look-up tables. The &agr;ROMs are addressed using the first signal to provide a first address component and using the second signal to provide a second address component. Modula mathematics are performed utilizing the values from the &agr;ROMs to generate error correction data. The error correction data is in groups each having a second predetermined number of elements. A RAM is accessible by a Trellis encoder and has an array for holding the information data elements and error correction data elements.