Optimal Operating Point of the Power Amplifier with respect to the EVM for TV Broadcasting Applications
Résumé
"The high Power Amplifier (PA) dominates the power
consumption in DVB transceiver systems and requests focusing
the power efficiency improvements on this device; especially when
multi-carrier modulations are used which is characterized by
high Peak-to-Average Power Ratio (PAPR). In this paper, first,
we provide analytical expression of the Error Vector Magnitude
(EVM) of the amplified signal when polynomial predistortion
and clipping techniques are activated. Secondly, a theoretical
analysis of the trade-off between the power amplifier linearity
and efficiency is investigated considering the performance of the
clipping and predistortion techniques. Therefore, an analytical
expression which gives the optimal Input Back-Off (IBO) maximizing
the PA efficiency, with respect to an EVM constraint,
is provided. It is demonstrated that significant power efficiency
improvement can be achieved using our analytical expressions"