Network Strategies Of Wireless Communication System To Enhance Cell Edge Performance

With increasing demands for numerous users and various services, the wireless communication systems for higher data rate have been developed. While during the current wireless communication systems, the service quality differs a lot at the cell edge and the cell center, in order to guarantee user experience, methods to solve the cell-edge problem is urgent to be found. Meanwhile, for high spectral efficiency, good anti-multipath interference effect and low baseband processor complexity, OFDMA has been utilized in various wireless communication systems and become the trend. Now, LTE/LTE-A based on OFDMA has become the most popular standard after3G and been broadly supported by wireless communication operators and manufacturers, pre-commercial tests for TD-LTE have been conducted in China. In this thesis, the cell-edge problem LTE/LTE-A is chosen as the research area.This thesis mainly analysis the cell-edge performance problem and proposes corresponding network strategies to improve the performance. The main contributions are as following:The effect factors, features and challenges are analyzed. The current strategies to improve the cell-edge performance are summarized and researched on system cost, spectral efficiency and performance enhancement. These achievements guide the research direction of this thesis.Two network strategies to improve the cell edge performance, one is combination of multi-hopping mode with HII, the other is distributed180degree antennas system. Following the description of system model, performance analysis and simulation are conducted. The network model for the first strategy is described on strategy description, resource scheduling, strategy feature and implementation procedures. The model of the other strategy is also introduced on resource scheduling, interference suppression and handover. The numerical expression for capacity, energy efficiency and cell edge throughput are derived. Eventually, the corresponding conclusion is made by the performance simulation. The first strategy can improve cell throughput and cell-edge performance, especially for the high load scenarios. And the second strategy can improve the capacity, energy efficiency and cell edge throughput performance. It is the effective strategy to solve the cell-edge problem.