Performance of Distributed-Antenna DS-CDMA Systems Over Composite Lognormal Shadowing and Nakagami-$m$-Fading Channels

This paper investigates the uplink performance of a high-capacity direct-sequence code-division multiple-access (DS-CDMA) wireless communication system, where numerous antennas are distributed in the area covered by the system. Following the description of the system, typical characteristics of the distributed-antenna DS-CDMA (DA/DS-CDMA) system are summarized, in comparison with conventional DS-CDMA systems that employ centralized base station (BS) antennas. Then, the bit error rate (BER) performance of the DA/DS-CDMA system without using power control is investigated when the low-complexity correlation and minimum mean square error (MMSE) detectors are employed and when composite transmission pass loss, lognormal shadowing slow fading, and Nakagami- m fast fading are considered. Our analytical and numerical results suggest that the DA/DS-CDMA system constitutes a high-power-efficiency wireless system. For the same set of system parameters, the DA/DS-CDMA system is capable of providing a much higher capacity than the conventional DS-CDMA system. The DA/DS-CDMA system can be free from power control. Furthermore, the hand-over in the DA/DS-CDMA system is also very simple.