Interference Aware Handoff with Interference Alignment for Cellular MIMO Networks

This paper presents the use of channel degree-of-freedom (DoF) as criterion for handoff in the co-channel cellular network to improve the system capacity and quality of service (QoS). In cellular networks, the popular received signal strength indicator (RSSI) based handoff scheme does not consider the inter-cell interference (ICI) in the network. However, the overall system capacity performance is subject to the ICI. The sum rate based handoff scheme takes the interference into account, however, the complexity is quite high. In this paper, by adopting interference alignment technique, we present a DoF based handoff scheme for the co-channel multiple-input multiple-output (MIMO) network. We have developed a tree based handoff scheme with the DoF as the decision criterion. We find that the proposed scheme is especially beneficial to the edge users as compared to the RSSI scheme. Furthermore, we have developed a joint approach that combines both RSSI and DoF criterions in the handoff scheme to adapt to the near far channels in the network. The proposed scheme is compared with the RSSI-only and the sum rate based handoff schemes. The simulation results show that the interference aware handoff scheme is beneficial to system capacity, especially for the cell edge