Concurrent communications with adaptive interference cancellation in MIMO networks

Exploitation of the spatial dimension in MIMO systems enables co-channel concurrent transmissions between the nodes, thus increases the capacity of the network. A major challenge in the implementation of concurrent transmissions is the mitigation of the interference without causing excessive communication overhead in the network. In this paper, we present a low overhead Concurrent Communications scheme based on Adaptive Interference Cancellation (CC-AIC), which does not require any explicit channel estimations between the nodes in the network. By using the adaptive RLS algorithm for interference cancellation and PN sequence based preamble, we address the channel estimation and communication overhead problems of the previous Space Division-Carrier Sense Multiple Access (SD-CSMA) based protocols. Simulation results show that the proposed scheme effectively cancels the interference caused by other concurrent communications and delivers an aggregate network throughput that is 29%-78% higher than that delivered by the existing SD-CSMA based protocol. In addition, we present experimental results on the interference cancellation performance of the proposed method to prove the practicality of our method.