Performance of a FH Multilevel FSK for Mobile Radio in the Presence of Nonsynchronous Users

This paper considers a Frequency Hopped Multilevel Frequency Shif Keying (FH-MFSK) spread spectrum communication system applied to mobile radio-telephony. We pre sent a mobile-to-base transmission model that allows to study system impairments, such as interference from nonsynchronous users and adjacent frequency channels in presence of matched tuned receiver filters. We have obtained results with mobile-to-base communication of 32 Kb/s per user in a 20 MHz (one-way) bandwidth. A bit error probability less than 10
^-3
can be maintained with up to 110 simultaneous users for practical average SNR ratio of 25 dB.