A phase shift technique for intermodulation cancellation

In a multi-carrier transmission system, intermodulation distortion (IMD) is generated because of amplifier non-linearities. The presence of IMD degrades the performance of such systems. In this paper, an IMD cancellation technique based on phase shift is presented. The technique depends on applying pre-determined phase shifts to each carrier signal before they are combined. Then, an increased number of amplifiers are used to enable the cancellation of chosen IMD components. The amount of phase shift depends on the frequency components to be cancelled. Simulation results are presented to show the effectiveness of the technique proposed.