Optimization of SHO margin in WCDMA network

The focus of the paper is to analyze the downlink performance of a wideband code division multiple access (WCDMA) system with site selection diversity transmission (SSDT) power control during soft handover (SHO) mode and to find the optimum SHO margin (M_SH) in terms of maximum system capacity under energy-per-bit to noisespectral density ratio (Eb/No) quality requirements. Analyzing the dependency of the connection probabilities, percentage of users connected to one, two, or three Base Stations (BSs) simultaneously as a function of the M_SH. Analyzed the system capacity and required resources dependency on M_SH for voice service and combined multimedia mobile services. System capacity dependency on M_SH is analyzed, by considering two types of user distributions, namely 1) uniform user distribution and 2) a concentration of all the users in the location that requires maximum transmitted power (the worst case). The result of this analysis shows an increase in user capacity of about 16% - 20% for the optimum MSH of 5-5.5dB. Nevertheless, the resources required (number of scrambling codes) by the base station increases faster than the number of active users in terms of M_SH.