摘要(英) |
In mobile communication systems, both uplink and downlink resources are allocated by the base stations. However, neighboring base stations can cause a decrease in the overall system throughput due to inter-cell interference (ICI), especially for User Equipment (UE) at the cell edge. Additionally, since 5G utilizes higher-frequency bands compared to 4G, the signal attenuates faster, requiring a denser deployment of base stations to achieve the same signal coverage as 4G. Therefore, the area where ICI occurs will be denser. To mitigate the impact of ICI, neighboring base stations communicate and coordinate with each other, determining resource allocation based on the coordination results. This approach helps suppress the effects of ICI, improving the throughput of Cell-edge UEs and further enhancing the overall fairness of UEs. The method of resource allocation is a primary factor that affects the overall throughput and fairness of the system, while Inter-cell Interference Coordination (ICIC) between base stations is a secondary factor. However, with an increasing number of Cell-edge UEs and non-uniform distribution of UEs, the impact of ICIC on throughput and fairness becomes more significant. Therefore, this thesis will analyze in this direction.
This thesis combines four scheduling schemes, namely Maximum Rate (MR), Proportional Fair (PF), Opportunistic Proportional Fair (OPF), and Round Robin (RR), with four ICIC schemes: Reuse 1, Soft Frequency Reuse (SFR), Muting, and Joint Transmission Coordinated Multi-Point (JT CoMP). These sixteen methods are simulated using a 5G C-RAN architecture in a scenario with seven base stations. The simulation results analyze and compare the throughput and fairness. The sixteen methods are divided into four groups based on the scheduling scheme for further discussion, considering the influence of the four ICIC schemes under different UE distributions. In general, the PF scheduler finds a balance between the overall system throughput and fairness. The OPF scheduler offers a new option that lies between MR and PF in terms of throughput and fairness. In most cases, JT CoMP offers the highest throughput for Cell-edge UEs and also achieves the highest level of fairness. |
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