Improved power efficiency for DVB-SH transmitters

Power efficiency is an important criterion for modern communications systems. It is well known that due to its high Peak-to-Average Power Ratio (PAPR) the Orthogonal Frequency Division Multiplexing (OFDM) modulation scheme presents serious power efficiency problems related to the High Power Amplifier (HPA) of the transmitter that are critical in satellite systems like Digital Video Broadcasting Satellite to Handheld (DVB-SH). In order to improve the power efficiency we propose to apply to DVB-SH the Active Constellation Extension (ACE) algorithm as a PAPR reduction method. Additionally we also present a new ACE optimization criterion: the reduction of the cubic metric (CM). The minimization of both metrics provides an important improvement of the out of band distortion and the Output Back Off (OBO) of the amplifiers, and consequently an increase of the HPA power efficiency.