Dynamic Inter-cell Interference Cancellation for Uplink in Multi-cell OFDMA Systems

摘要

In this study, we consider the joint application of adaptive Soft Frequency Reuse (SFR) and Maximum Ratio Combining (MRC) to dynamic Inter-Cell Interference (ICI) cancellation. The ICI is the dominant factor in system performance degradation for uplink in multi-cell Orthogonal Frequency Division Multiple Access (OFDMA) systems. This study firstly investigates the problem of ICI for uplink. Then dynamic ICI cancellation for uplink in OFDMA systems is proposed. When loading is small, low complexity and practical adaptive soft frequency reuse is adopted. As users in the boundary grow larger, MRC is applied to improve edge user performance, which can also cancel ICI by reducing user transmission power. Analysis results show the proposed scheme can provide better reuse efficiency over the adaptive SFR and also can mitigate ICI significantly. Simulation results indicate that the ergodic capacity proposed scheme increases larger 14.5% than not using MRC for E_s/N₀ around 10 dB. Higher spectral efficiency is achieved for large number of users in multi-cell environments, especially for users at the cell boundary.