PRE-DISTORTION USING A BY-PASS SIGNAL

摘要

The present method disclosed presents a solution to the problem that a fairly large bandwidth has to be associated with the distorted signal used for pre-distortion. According to the present disclosure the method applies different D/A converters for the two signals involved, i.e. for the original digital message signal (A-branch) and the pre-distorted digital signal part (B-branch). In other words, it is suggested to use the same high resolution and moderate sampling frequency D/A converter as used conventionally according to the state-of-the-art, but to use a low resolution with a higher sampling rate D/A for the added pre-distortion signal. The two signals are then combined in their analog domain. Thus, requirements on high sampling rates for both signals at the same time are avoided. Care of course has to be taken to ensure that the two added signals have the proper time alignment or phase alignment.