GMSK/DS spread-spectrum signaling with two-bit differential detection over mobile channels with frequency-selective fading

The performance of GMSK/DS spread-spectrum signaling with binary phase-shift-keying and two-bit differential detection operating in a fast Rayleigh frequency dispersive mobile channel is investigated. A generalized channel model, that takes into consideration the presence of faded cochannel interference signals, is used for analysis. Closed form expressions are derived for the average error probability and are numerically evaluated for many channel conditions. The results clearly show that the incorporation of DS signaling, with relatively small processing gain, highly improves the performance of GMSK in severe channel degradation environments