Power efficient back-off reduction through polyphase filtering magnitude modulation

A multistage polyphase magnitude modulation (MPMM) technique is proposed for single carrier (SC) modulations, to efficiently reduce the peak-to-average power ratio (PAPR) of the bandwidth limited signal resulting from root-raised cosine (RRC) filtering. We show that the application of back-off to the transmitter high-power amplifier (HPA), in order to avoid nonlinear distortion and thus spectral regrowth, can be almost eliminated, even at very low roll-off values, leading to systemiquests high power efficiency. We also show that noise sensitivity due to MPMM is considerably minimized by improving the initial receiver´s soft-decoding estimates, based on the average positions of the MPMM constellation symbols.