Non-overlapping conditions to enable multi- dimensional behavioral models/dpds for multi-band or non-continuous carrier aggregation systems

Abstract

To linearize the multi-band PAs/ transmitters, a serial of multi-band predistortion models based on multi-dimensional architecture have been proposed. However, most of these models work properly only for the signals whose harmonic and intermodulation products of carriers' non-overlap with the interested fundamental bands. In this paper, the non-overlapping conditions for dual-band and tri-band signals are derived and denoted in the form of closed-form expression. It can be used to verify whether a given dual-band/ multi-band signals can be linearized properly by these multi-dimensional behavioral models. Also the conditions can be used to plan the frequency spacing and maximum bandwidth of a multi-band or non-continuous carrier aggregation signal. Several dual-band and triband signals were tested on the same PA, by employing 2-D DPD and 3-D DPD behavioral models. The measurement results show that the signals which don’t satisfy the non-overlapping conditions cannot be linearized well by the multi-dimensional behavioral models which does not take the harmonic and intermodulation products of carriers' into account.