Transmitter linearized in response to signal magnitude derivative parameter and method therefor

Abstract

A transmitter () includes a low power nonlinear predistorter () that inserts predistortion configured to compensate for a memoryless nonlinearity () corresponding to gain droop and another memoryless nonlinearity () corresponding to a video signal. When efforts are taken to reduce memory effects, such as configuring a network of components () that couple to an HPA () to avoid resonance frequencies within a video bandwidth (), high performance linearization at low power results without extending linearization beyond that provided by the memoryless nonlinear predistorter (). A look-up table () has address inputs responsive to a magnitude parameter () of a communication signal (), a magnitude derivative parameter () of the communication signal (), and possibly one or more variable bias parameters (). The look-up table () produces a gain-correcting signal () that adjusts the gain applied to the communication signal () prior to amplification. The look-up table () is updated in response to an LMS control loop.