Downlink soft handover gain in CDMA cellular network with cross-correlated shadowing

A relatively accurate model for shadowing cross-correlation is taken into account to evaluate the performance of downlink, in hard handover and soft handover based CDMA cellular systems. Two special shadowing cases i.e. independent and constant cross-correlated shadowing processes are also evaluated for the comparison purpose. The performances of the two systems are compared in terms of the distribution of received pilot C/I, outage probability and the effective cell coverage, to evaluate the soft handover gain. The simulation results show that, under different shadowing models, soft handover system outperforms hard handover with a considerable gain. It has also been observed that the shadowing cross-correlation must be taken into account for accurate soft handover analyses. However, using a constant cross-correlation of 0.5 i.e. often used in the literature over-estimates the C/I in the systems.