Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
The giant ever increasing demand for higher data rates and better Quality of Service (QoS) is rapidly growing and operators’ main concern is to support the growth of mobile data traffic and address the users’ expectations while at the same time keeping the costs of services reasonable , , . This is more vital in residential and dense urban areas where the reception of the macro signal level becomes weak . Therefore, the implementation of ultra dense networks becomes a promising approach which is expected to provide good indoor coverage and higher capacity in residential areas. Nevertheless, the potential degradation of network performance due to severe interference originated from nearby networks should be deeply studied prior to full-scale implementation of ultra dense networks. The main concern of this thesis work is to investigate the coexistence between two operators in Time Division Duplex (TDD) system which are using adjacent frequency channels and implemented in the same geographical area. For this purpose, the system level simulation based on Monte Carlo method is performed to reveal the impact of critical parameters including Adjacent Channel Interference power Ratio (ACIR), Uplink-Downlink synchronization between operators, Base-Stations positioning, and Internal walls existence on the system performance. Afterwards, the effect of densification on the previous findings is studied.
Results show that in downlink and uplink, approximately 30 dB and 55 dB of ACIR is required, respectively, in order to eliminate the impact of adjacent channel interference. Furthermore, in uplink, synchronization is necessary when base stations of operators are collocated. In downlink, however, synchronization and collocation is beneficial when signal quality is poor. On the other hand, it is shown that densification is feasible provided base stations employ adjustable transmission power model. Moreover, internal walls can improve system performance due to attenuation of interferences originated from surrounding cells.
2013. , 70 p.