PERFORMANCE ANALYSIS OF FSK MODULATIONWITH LIMITER-DISCRIMINATOR-INTEGRATOR DETECTION OVER HOYT FADING CHANNELS

摘要

The focus of this paper is on the performance analysis of frequency shift keying (FSK)modulation with limiter-discriminator- integrator (LDI) detection over frequency-flat Hoyt (Nakagami-q) fading channels. Specifically, a closed-form expression is derived for the probability density function (PDF) of the phase difference of Hoyt faded FSK signals disturbed by additive white Gaussian noise (AWGN). This newly derived PDF is verified to reduce to known results corresponding to the Rayleigh fading channel as a special case of the Hoyt model. The validity of the expression is further demonstrated by simulation for the case of a Hoyt mobile-to-mobile (M2M) fading channel. The analytical PDF of the phase difference is then applied to determine the bit-error probability (BEP) of the LDI receiver taking into consideration the Doppler effects, the click noise as well as the inter-symbol interference (ISI) caused by the intermediate frequency (IF) pre-detection filter. Numerical examples, assuming a Hoyt M2M channel, are given to illustrate the analysis and examine the effects of the FM system parameters and the fading characteristics on the BEP performance.