Forward link capacity losses for soft and softer handoff in cellular systems

In CDMA cellular systems, all radio channels use the same frequency band, and the same radio channel can be reused in all neighboring cells. On the forward link there are at least two base stations involved in the soft handoff process, where each base station supports a forward link channel to the mobile, this produce capacity gain by macrodiversity and produce capacity loss due to the use of extra channels. In this paper the losses of soft and softer handoff on the forward-link capacity for unsectorized and sectorized cells due to the use of at least two BSs in the handoff process are evaluated analytically. We follow two approaches, the deterministic approach and the random approach (considering shadowing) and we take into account the IS-95 standard. We obtain that the capacity loss is approximately from 13% to 25% depending of propagation parameters values and handoff threshold.