| Although it is well known that the reverse link coverage of a cell has an inverse relationship with the user capacity in a Code Division Multiple Access (CDMA) cellular system, our literature review has found only one published paper that analyzes this important issue and provides some quantitative results.; An accurate prediction of cell coverage as a function of user capacity is essential in CDMA network design and deployment, and is therefore of great interest. The results presented by the previous research are based on only one possible approach. Because CDMA is the primary technology being developed for 3G systems, there is great need and interest in further investigation of this issue. Thus, our research objective is to develop rigorous methods for estimating the coverage vs. capacity tradeoff in the reverse link of CDMA cellular systems and to then predict average reverse link coverage.; In this dissertation, we first review the basics of mobile communication and CDMA cellular systems. We then describe the instantaneous outage approach used in the previous work to derive the relationship between cell coverage and capacity in a CDMA system and we analyze some of the limitations of this approach. Using this foundation, we develop a theoretical framework to analyze the coverage vs. capacity tradeoff and estimate the reverse-link single-cell coverage for CDMA cellular networks based on a duration outage criterion. We also analyze the impact of multipath fading on the CDMA cell coverage estimates. In addition to single-cell coverage, we also analyze reverse-link two-cell coverage including the impact of soft handoff. Based on this, we also analyze the tradeoff between capacity improvement vs. coverage expansion due to soft handoff. Further, we describe a simple algorithm for designing multi-cell coverage that is useful for planning the topology of a CDMA cell networks. In total, the results of this research provide a comprehensive framework for designing the topology of CDMA cell networks to achieve specific coverage and capacity requirements. Finally, we extend our coverage vs. capacity analysis to include multi-rate services allowed by wideband CDMA cellular systems. |
