How much PAR to bring to the party?

In English Reducing Peak-to-Average power Ratios (PAR) is an established research topic that has now begun to find its way into products. This gives rise to new questions of dimensioning. Here we address how much PAR reduction that
should be applied in a practical system. We demonstrate
that the amount of PAR reduction can be found with the
appropriate system models. This is applied to the tonereservation PAR reduction method in an ADSL system.
In some frequency regions, the SNR is in practice often
limited by the dynamic of the transmitter’s analog frontend. Other frequency regions are strongly attenuated by the channel and contribute very little to the system’s capacity. Using multicarrier modulation, we address how
much of the spectrum that could be used to improve the
SNR in the other regions by reducing the amplitude swing
of the transmit signal.