Interference Precancellation for Resource Management in Heterogeneous Cellular Networks

Network densification by installing more cellular stations (cells) with smaller coverage is promising to improve wireless capacity to meet the explosive growth of cellular traffic. The macrocellular base station and smaller cells with different coverage form heterogeneous cellular networks. Typically, the smaller cells operate in the same spectrum as the macrocells. Most of the existing interference mitigation approaches either rely on resource isolation or power auto-configuration. In cellular networks, the data to all cells and the mobile stations (MSs) are originated from the core cellular network. We take advantage of this characteristic and propose a technique called interference precancellation. If the exact interferer to an MS is identified, the victim cell that serves the victim MS transmits the interference precanceled signal, which is the signal intended for the victim MS subtracts the interference signal. The interference precanceled signal and the interference signal scramble at the victim MS and became the intended signal. With interference precancellation, the interferer and the victim cell can utilize the same set of resources and thus the capacity is further improved. However, some MSs are interference-free, and for MSs whose exact interferers cannot be determined, the MSs still require resource isolation. Therefore, we propose an algorithm for resource management with interference precancellation (RMIP) that jointly considers MSs experiencing a different level of interference. Through experiments on GNU Radio/USRP, we show that the known interference signal can be precanceled and the combination of the interference signal and the precanceled signal becomes the intended signal. Simulation results show that if all exact interferers are identified, RMIP algorithm achieves higher throughput compared with pure resource isolation.