Ressourcenallokation in LTE-Netzen unter Ber├╝cksichtigung von Interferenz und heterogenem Verkehr

Elektrotechnik Diplomarbeiten (August 2011 - Februar 2012) net


Michael Reyer,


Orthogonal Frequency Division Multiple Access (OFDMA) is considered one of the prime transmission technologies of wireless broadband networks, e.g., IEEE 802.16a/e, LTE Advanced. For resource allocation in OFDMA based networks, interference mitigation is one of the major challenges. Furthermore, the development trend of wireless applications is to mix a variety of services such as VoIP, video call, Email, and TCP/IP traffic. The thesis deals with the Resource Allocation (RA) problems in LTE for different classes of services taking interference of neighboring cells into account. This leads to a heuristic algorithm of Interference Aware Resource Allocation (IARA) for maximizing the total throughput in the system by control of inter-cell interference among cells. In our model, the two kinds of services considered are Guaranteed Bit Rate (GBR) services with rate demands and Best Effort services without rate requirements. We apply IARA to solve RA for Guaranteed Bit Rate services with fixed rate demands first. Based on the achieved results, resource allocation schemes for a mixture of GBR services and BE services are derived. Furthermore, load imbalance exists and deteriorates the system performance of LTE. Thus, a framework of Load Balancing (LB) is proposed. The previously suggested schemes of RA combined with LB are investigated as well. Comparison and analysis of the performance of suggested algorithms are conducted based on the assessment criteria: number of dropped users, system throughput, and resource utilization. Simulation results show the potential of such approaches and RA schemes with LB outperform consistently schemes without LB in terms of small number of dropped users, significantly higher system throughput in the available bandwidth.