On the spectral efficiency of different coherent techniques for frequency comb multiple access systems

Abstract

The spreading of M-ary signaling frequency comb multiple access (FCMA) signatures over different radio modulation techniques is investigated. Detection has been carried out coherently for AWGN communication channels including cochannel interference. The dependence of bit error probability on the signal to noise ratio, the number of simultaneous accesses, and the number of frequencies per signature are given as parameters. Coherence detection FCMA among FSK has indicated an improvement of FCMA systems capacity. The different modulation techniques performance is presented and spectral efficiency estimated. New systems results indicated 0.3 b/s/Hz compared to a maximum of 0.22 for the noncoherent M-ary FCMA.