Analytical Analysis of Polyphase Magnitude Modulation Method´s Performance

An efficient multistage polyphase magnitude modulation (MPMM) scheme was recently proposed to solve the problem of controlling the envelope´s power peak of single carrier modulated signals, band limited by root-raised cosine (RRC) pulse shaping filters, in order to maximize the efficiency of the transmitter´s high power amplifier (HPA). This paper addresses the statistical analysis of MPMM coefficients and performs an analytical study of the average power and the peak-to-average power ratio (PAPR) of the magnitude modulated transmitted signals. It is shown that the average power losses due to MPMM are largely compensated by the outstanding back-off reduction gains, leading to an effective reduction on the transmitted signal´s PAPR. The analytical study also shows that these losses are comparable to those observed with the clipping method (less than 1dB), without generating the undesirable spectral regrowth effect.