BER analysis for a FFH spread spectrum system employing DPSK modulation over a Rayleigh fading channel

This paper presents a comparative study of the use of two modulation techniques for a fast frequency hopping (FFH) spread spectrum system for wireless communication over a non-selective Rayleigh fading channel. The modulation techniques considered are binary frequency shift keying (BFSK) and differential phase shift keying (DPSK). The comparison standard chosen is that of the signal-to-noise ratio (SNR) for achieving a given bit error rate (BER). It is found that DPSK is capable of giving a gain of about 3 dB over BFSK indicating the potential for employing DPSK for such a spread spectrum. A square law combiner for the case of DPSK has also been suggested.