Title :
Limiter discriminator detection of M-ary FSK signals
Author :
Fonseka, John P.
Author_Institution :
Sch. of Eng. & Comput. Sci., Texas Univ., Dallas, TX, USA
Abstract :
The performance of limiter discriminator detection of M-ary FSK signals is analysed at arbitrary modulation indices. It is shown that the error rate performance of limiter discriminator detection can be significantly improved by increasing the modulation index above 1/M. The optimum modulation index that minimises the overall error probability is determined for the cases M=2, 4 and 8. The analysis is carried out for wideband and bandlimited channels with Gaussian and second-order Butterworth filters. It is shown that the optimum modulation index depends on the signal/noise ratio (SNR), in a wideband channel, and on both SNR and time-bandwidth product in a bandlimited channel. Finally, it is shown that the optimum sampling instance in presence of a nonzero phase IF filter can be approximately determined by using only the worst case symbol pattern.<>
Keywords :
demodulation; discriminators; error statistics; filtering and prediction theory; frequency shift keying; limiters; signal detection; telecommunication channels; Gaussian filters; M-ary FSK signals; SNR; bandlimited channels; error probability; error rate performance; limiter discriminator detection; modulation index; nonzero phase IF filter; optimum sampling instance; second-order Butterworth filters; signal/noise ratio; time-bandwidth product; wideband channel; worst case symbol pattern;
Journal_Title :
Communications, Speech and Vision, IEE Proceedings I
