Cooperative Interference Cancellation in Multi-hop Wireless Networks: A Cross Layer Approach

Multi-hop wireless networks are expected to play a key role in the next generation wireless systems. In such networks, the presence of multiple links may create severe interference during signal reception and this will greatly limit the network capacity. There has been a lot of work on interference cancellation in single-hop wireless networks. However, how to effectively mitigate interference caused by multi-hop transmission has not received much attention. This paper presents a cross-layer approach for interference cancellation in multi-hop networks. Specifically, two cooperative interference cancellation strategies, which we shall refer to as decode-and-cancel protocol and amplify-and-cancel protocol, are proposed. These schemes take advantage of the presence of a common packet being transmitted through the multiple nodes or hops. It is shown that at a given interfered node, the interference can be estimated and cancelled based upon the received signal of this common packet during the preceding hops. We shall derive the capacity regions of the proposed two protocols and show that they can significantly increase the link capacity.