ARC-FSK-a new anti-multipath modulation for mobile and personal communications systems

A novel asymmetric-raised-cosine frequency shift keying (ARC-FSK) digital modulation with superior anti-multipath characteristics is proposed. The new modulation is significantly more robust than the popular GMSK/GFSK in multipath radio propagation environment. Our theoretical analysis and computer simulation studies show that the new ARC-FSK modulation has the ability to speed up conventional PCS and indoor wireless LAN systems (currently using GMSK/GFSK) by more than two times without channel equalizer, The penalty is a mere 14% reduction in spectral efficiency. Another attractive feature of ARC-FSK is its full compatibility with conventional GMSK/GFSK. We conclude that the ARC-FSK modulation is ideal for high speed low cost TDMA/PCS and indoor wireless LAN systems where both high power/spectral efficiency and simple modem structure are desired.