Impact of Adjacent Channel Interference on the Capacity of WCDMA/FDD Networks

Adjacent channel interference (ACI) can result in a reduced network capacity in a multioperator WCDMA/FDD environment. This paper is devoted to the study of the ACI by using a static simulator. Simulations were performed in order to identify particular scenarios and network compositions where ACI plays a major role in the system capacity. On the basis of the results, the authors identify the best strategy for frequency deployment, within the available spectrum, is identified. It is demonstrated that the macro carrier should be located in the centre of the frequency band, protected from the ACI introduced by other operators. It is, in fact, the carrier which suffers the greatest losses due to the increase in ACI. Furthermore, the micro carrier should be placed as close as possible to the adjacent channel of other operators in order to maximize system capacity.