Load analysis of the soft handoff scheme in a CDMA cellular system

In a code-division multiple-access cellular system, the soft handoff with m acrodiversity is known to increase the number of available channels in each cell from the interference-reduced radio environment. This capability, how ever, also incurs extra load on the system due to the increase In the numbe r of channels occupied and reserved for macrodiversity. The objective is to evaluate the associated loads, thereby enabling effective channel manageme nt, We first differentiate two kinds of loads attributable to new and hando ff calls, respectively. Further dividing handoff calls into two kinds, we d erive a load balance equation from which three different loads at a cell ar e all exactly obtained in association with the size of the soft handoff reg ion. Comparative analysis with the case of no soft handoff region, i.e., of hard handoff, shows the appropriate proportion of channels reserved for th e macrodiversity in a given soft handoff region.