Acquisition performance study of single- and multi-carrier DS-CDMA over Nakagami-m fading channels

We investigate and compare the initial acquisition performance of singleand multicarrier DS-CDMA systems over multipath Nakagami-m fading channels under the hypothesis of multiple synchronous states in the uncertainty region of the PN code. The code acquisition performance is evaluated in the context of multi-carrier DS-CDMA (MC DS-CDMA), when the correlator outputs of the subcarriers associated with the same phase of the local pseudo-noise (PN) code replica are noncoherently combined using an equal gain combining (EGC) scheme. Our investigations indicate that the code acquisition performance of the MC DS-CDMA scheme is better, than that of the single-carrier DS-CDMA scheme over the multipath Nakagami-m fading channels encountered. However, if the detection threshold was set inappropriately, the performance might be degraded, even if the channel quality improves.