Power allocation strategies for the downlink in a W-CDMA system with soft and softer handover: the impact on capacity

In this paper, the power allocation strategy in the downlink of a W-CDMA system is investigated, with the aim of assessing the network capacity. It is known that the downlink capacity for a base is limited by the maximum transmit power, which is a common resource to be shared by all users; if one user requires a large fraction of the allowed transmit power, the overall capacity could be decreased: in the work herein we analyse the impact on the capacity of a power allocation strategy which limits the maximum fraction of transmit power per link. A semi-analytical model is developed, considering a classical propagation model and taking soft handover and a multi-service scenario into account. The results show cell capacity as a function of some interesting parameters, such as the cell radius and the number of bases included in the active set. Both the cases of omni and sectorised cells are considered.