METHOD AND APPARATUS FOR PROVIDING A CARTESIAN TRAINING WAVEFORM

摘要

One provides (401, 402) both an in-phase signal component (501) and a quadrature signal component (601) wherein the latter has a non-zero portion. These two signal components are then combined (403) to provide a Cartesian training waveform that can be used when training a linear amplifier that uses Cartesian feedback linearization. By one approach, the non-zero portion of the quadrature signal component can be coincident with a zero-crossing portion of the in-phase signal. In many application settings this non-zero portion of the quadrature signal component can be less (and sometimes considerably less) than a peak amplitude of the in-phase signal component. One may also shape the in-phase signal component to have a smoothed envelope. This may include, for example, using a smoothed sine wave such as a raised-sine function.