Effect of Ideal Inter-Cell Interference Cancellation to HSDPA System Performance

High speed downlink packet access (HSDPA) concept in wideband code division multiple access (WCDMA) system provides spectrally efficient packet access connection by means of dynamic link adaptation, low spreading factor and higher order modulation. Due to these the achievable data rate is vulnerable to the interference both from the serving cell and from the neighboring cells. Several linear and non-linear interference mitigation methods have been presented in literature to mitigate mainly the intra-cell interference but similar algorithms can also mitigate the inter-cell interference at the cell border area. However, the effect of inter-cell interference cancellation has not been thoroughly evaluated in system level. In this paper we analyze the system performance of an ideal inter-cell interference cancellation in HSDPA network. The analysis considers also traditional advanced receivers, which mainly suppress or cancel intra-cell interference. Linear minimum mean square error (LMMSE) chip equalizer and receive diversity are considered. The modeling of inter-cell interference mitigation at the UE receiver is not modeled explicitly but is based on removing a predefined portion ideally from the interference produced by selected number of strongest interfering sectors. By this way, the interference cancellation efficiency can be mapped to the actual system performance improvement. The results are obtained from a fully dynamic system simulator, where the mobility of UE´s and radio resource management algorithms are modeled.