BER performance of anti-multipath modulation scheme PSK-VP and its optimum phase-waveform

This paper proposes a new anti-multipath modulation scheme, which the author calls PSK-W (phase-shift-keying with varied phase), in which a time-varying phase-waveform is redundantly imposed on the DPSK timeslot. The relationship between the phase-waveform and BER (bit-error rate) is discussed by using an analytical approach which considers the diversity of received signal components that are continuously varying over a symbol period. A formula-type BER expression obtained by this analytical approach yields a maximum-diversity phase-waveform condition. A convex phase-waveform is considered to be the best choice because of this condition and an additional consideration for spectrum compactness. A numerical evaluation confirms the performance of PSK-VP with a convex phase-waveform and reveals a band-limitation effect. From the numerical evaluation, it is shown that the 4-ary version of PSK-VP with a convex phase-waveform has an excellent BER performance in multipath fading when the delay dissipation is less than 1.7 bits, although requiring about twice the bandwidth due to the imposed phase redundancy