Impact of Clipping on EVM of the Predistorted Non-Linear Amplified Multicarrier Signals
Abstract
In this paper, we analyse the impact of the clipping technique on EVM of multicarrier signals, assuming that the transmitter is equipped with a linearization stage before the PA. Therefore, the expression of the Error Vector Magnitude (EVM) of the output signal is analytically derived with and without the use of the predistortion and/or the clipping technique. We provide analytical expressions of the EVM in the form of a series expansion that depends on the transition factors of the PA, the predistortion characteristics, the PAPR of the input signal and the clipping threshold. We show through simulations that the proposed expressions present very good accuracy, even when limiting the series expansion to an order of 4. Finally, a simple scenario is proposed to demonstrate the benefit of our EVM expressions in controlling the average transmitted power with the aim to guarantee a high quality of service.