We propose an analysis of reverse link CDMA multispot beam stratospheric platforms (SPF) in this paper. The SPF is
currently proposed as a novel wireless technology for the development of the next generation fixed and mobile
communications. The geometry of this technology is different from that of the terrestrial but rather similar to the
satellite based cellular system. However, evaluation on the CDMA system capacity of this technology has not been
much reported. This paper addresses all possible multiple access interference analyses including the effects of channel
fading and shadowing in order to evaluate the system capacity. Single SPF and multiple SPF model are evaluated under
perfect power control and imperfect power control. The results indicate that in SPF systems the reverse link CDMA
capacity is significantly reduced because of the power control imperfections. Moreover, in multiple SPF model the
interference caused by the users in overlapped region is not trivial. We found that because of this problem the capacity
is reduced for both speech and real-time data applications compared with the single SPF model even though the
assumption of perfect power control can be made. In order to improve the system capacity we proposed two methods,
first is to increase the minimum elevation angle definition for each platform and the second is to employ an adaptive
antenna.
