On the efficiency of fast frequency hopping multiple-access systems

The spectral efficiency of fast frequency hopping/multiple frequency shift keying (FFH/MFSK) multiple-access systems is investigated and its dependence on the basic system parameters is developed. Noncoherent MFSK signaling is studied in an additive white Gaussian noise (AWGN) channel. Chip synchronism and complex addition of signals having the same frequency are assumed at the hard-limited combining receiver. Based on the theory of circularly symmetric random vectors the probability of detection of the MFSK signals is calculated. It is shown that in many cases the optimum system parameters which maximize the spectral efficiency have to be chosen in such a way that the number of available system frequencies is equal to the parameter M of the MFSK signaling