Interference Analysis and Performance Evaluation on the Coexistence of Macro and Micro/Pico Cells in LTE Networks

3GPP Long Term Evolution (LTE) is the next generation network technology for beyond 3G. In the LTE system deployment, there may not be much separation between the frequency bands assigned to operators. Therefore, adjacent channel interference analysis between two coexisting LTE systems is a potentially important research field. In this paper, we investigate the coexistence problem between a macrocell and small cells, i.e., microcells and picocells, in LTE networks. We focus on analyzing the adjacent channel interference (ACI) between two coexisting systems with different duplex modes, i.e., frequency division multiplexing and time division multiplexing, deployed in adjacent frequency bands. Main contribution of this paper is to present the coexistence results of two systems by evaluating the macrocell performance degradation caused by ACI when it operates with microcell/picocell on adjacent channel in some typical interference scenarios. Based on comparison and analysis of simulation results, we find that in some scenarios two LTE systems could not coexist well under current LTE radio frequency requirements. We also present some suggestions and mitigation technologies to avoid large throughput loss due to ACI.