Out-of-Band Power Reduction using Selected Mapping with Power-Amplifier-Oriented Metrics

OFDM systems suffer from a high dynamic of the transmit signal, which leads to out-of-band radiation due to nonlinearities in the transmitter front-end. In order to overcome this issue there exist a variety of schemes reducing the out-of-band power. Most of these schemes consider the peak-to-average power ratio (PAR) as optimization criterion. In this paper, the PAR reduction scheme selected mapping (SLM) is extended to be used with other selection metrics such as the cubic metric (CM) or an amplifier oriented metric (AOM). Their influence on the out-of-band radiation is analyzed applying various amplifier models. It can be shown that out-of-band power is mainly caused by the clipping characteristic of an amplifier, which is sufficiently reflected by the PAR.