Partial response CPM in satellite mobile systems

It is known that Gaussian minimum shift keying (GMSK) is an attractive signaling technique in mobile communications. In this study, it is demonstrated using partial response raised cosine (ZRC) modulation that other partial-response continuous phase modulation (PR-CPM) techniques can perform better than GMSK in a mobile system. ZRC signals are analyzed and compared with GMSK signals in a mobile channel. Differential phase detection (DPD) and limiter discriminator detection (LDD) receivers with decision feedback are separately considered for the detection of the two types of signals. In case of ZRC signals, the delay of the DPD receiver, and the sampling instant of the LDD receiver are selected to minimize the error probability. Numerical results are presented for land mobile, satellite mobile and Gaussian channels at different bandwidths and Doppler shifts. It is shown that ZRC signals can perform better than GMSK signals at the same bandwidth.