Influence of Intercell Interference on HSDPA Indoor Networks

Nowadays the high demand of data based services has become one of the key issues in the telecommunications sphere. Mobile cellular networks are thus willing to provide the necessary capacity that this growth demands. While new third generation specifications keep on improving the HSPA and HSPA+ features, a parallel trend trying to provide enough indoor capacity is taking place. The performance of indoor dedicated systems is highly dependent on the interference present in the network. In this Thesis, the impact of intercell interference on indoor networks is studied. For that purpose, two different measurement campaigns were accomplished in Tampere University of Technology's Tietotalo building. The first of them was held in two small rooms, where picocells and distributed antenna systems (DAS) solutions were tested. The second campaign took place inside a large lecture hall representing an indoor open area, and here diverse picocell layouts were deployed. Analysis took into account interference indicators like signal-to-interference ratio and Ec/N0, and link adaptation parameters like CQI, modulation usage and transport block size. This Thesis provides guidelines for indoor planning. It demonstrates that in small rooms, given a fixed number of cells per room, picocells and DAS solutions show similar performance, so picocells are a better option since they require fewer components such as antennas. High-density cell layouts provide higher system TP, but the maximum system TP achievable is dramatically limited by interference. This Thesis also proofs that, in open areas, multicell layouts can give only a marginal increase in system TP with respect to one-cell layouts, and thus multicell configurations are not always needed to be deployed. High-interference regions need to be identified and cleverly located since they degrade the overall system performance and users in those areas experience unbearable low data rates. /Kir1