7.1 Introduction

CDMA2000 and WCDMA have many similarities as well as some differences. They use different types of channelization and spreading codes, pilot transmission schemes, coding, interleaving and modulations, physical channel structure, frame structure, power control, and handoff algorithms, as well as higher layer algorithms. These differences, however, have little impact on the system s relative coverage or capacity because they are optimized up to certain limits, mainly as a result of the required backward compatibility with their respective 2G systems (IS-95 and GSM). On the other hand, the fundamental difference spreading bandwidth affects the dimensioning process more significantly. Each CDMA2000 carrier uses 1.25 MHz of the total available bandwidth with a chip rate of 1.2288 Mcps, whereas WCDMA spreads the signals into a 5M-Hz band, using a chip rate of 3.6864 Mcps. A wide bandwidth gives additional diversity (i.e., improved capacity for WCDMA). A narrow bandwidth gives reduced own-cell interference (i.e., improved capacity for CDMA2000). Thus, the overall impact is small in most cases (i.e., CDMA2000 and WCDMA have similar basic performance). Since in general CDMA is an interference-limited system, it is always capacity limited. However, when the capacity is not the main issue, radio design will be based on the link budget and coverage. This is typically the case in the initial deployment of a new system or in the design of isolated rural cells, where the goal is to cover the area with a minimum number of base stations. Similarly, when reliable coverage for high bit rate indoor users from...