Improvement of frequency use and error performance of digital modulation in the personal mobile radios using quaternary-phase transition FSK (QTFSK)

A new modulation scheme, named QTFSK(Quaternary phase Transition FSK) is proposed for the digital land/satellite personal mobile radio applications. QTFSK is essentially a continuous phase FSK modulation scheme. It is demonstrated theoretically and experimentally that error performance of it is almost the same that of QPSK also in the Rayleigh fading channel, and further the occupied bandwidth or the main-lobe of the signal spectrum is narrower than QPSK.<>