Abstract: A high power RF transmitter that uses high power modulators that perform quadrature amplitude modulation (QAM) on a carrier signal after power amplification that is performed in the RF carrier source. The present invention transposes the locations of the modulators and power amplifier, and thus directly modulates a high power carrier signal. An RF carrier source generates a high power RF carrier signal that is split by a power splitter. A lookup table containing 2.sup.B words by K bits receives transmit data and mapping data and generates K-tuple modulating data. A plurality of phase key modulators are respectively coupled to outputs of the power splitter and to the lookup table and phase key modulate each of the signal components of the carrier signal using the K-tuple modulating data. A power combiner is coupled to outputs of the phase key modulators for outputting a high power QAM constellation from the transmitter.

Abstract: An equalizer that mitigates both linear and nonlinear distortions for amplitude phase keyed signals that are processed thereby. Algorithms employed in the equalizer are based on correcting received signals based on symbol transitions between successive symbols. The linear portion of the equalizer is programmable and can use any available algorithm. Programmable linear taps of the equalizer may be programmed in a nonlinear manner by using the lookup tables as amplitude dependent equalizers that are used to process one symbol at a time. In the equalizer, each amplitude level has it's own correction factor by using amplitude dependent coefficients. The equalizer can implement both linear and nonlinear equalization. Equalizer corrections are implemented using predetermined values stored in lookup tables. The equalization corrections are determined in an external computer and are loaded into the lookup tables for each amplitude level of the received signals.