Performance of an S-CDMA system with noncoherent spread-spectrum MSK modems
Gurgen H. Khachatrian, K.S. Kovakimyan, K.M. Nikogossyan, A.L. Vartapetyan · IEEE Transactions on Vehicular Technology · 1998
Simplified noncoherent and differentially coherent spread-spectrum (SS) minimum shift keying (MSK) receiver structures are presented. It is shown that an optimal noncoherent SS receiver for pure (with rectangular baseband pulses) offset QPSK signals can serve as a suboptimal (performance loss /spl sime/0.9 dB) noncoherent receiver for SS MSK signals. The conditions of orthogonality of SS MSK signals are derived in synchronous and quasi-synchronous code-division multiple-access (CDMA) systems. Computer simulation results evaluate the performance of the CDMA system with suggested receivers under certain conditions.