Abstract: A number of recent studies suggest that interference alignment approach the Shannon Capacity of interference networks at high SNR. The main idea of interference alignment is to align the interference from other BSs into the same channel space, while the local BS transmits own signal in the channel space free of interference. However, interference alignment scheme require global channel knowledge, while it is always impossible. In this work, we consider subspace interference alignment with the use of tri-sector antenna. In many works, basestation cooperation is considerd to decrease interference, while it causes inter-cluster interference. We adopt tri-sector antenna to cooperate 3 BSs in order to avoid inter-cluster interference. Further, the results of simulation show that the proposed algorithm can greatly reduce interference, and improve both the outage capacity and spectrum efficiency.