Understanding the benefits of successive interference cancellation in multi-rate multi-hop wireless networks

The performance of wireless networks depends on the achievable channel capacity for each transmission link as well as the level of spectrum spatial reuse in the network. For the latter one, successive interference cancellation (SIC) has emerged as an advanced PHY technique with the ability of decoding two or more overlapping signals, allowing multiple concurrent transmissions. In this paper, we seek to understand the benefits of SIC and its interference management capabilities in a multirate multihop wireless network. To characterise the network performance, we formulate the joint routing and scheduling problem with rate control as a mixed integer linear program (ILP) with the objective to maximize the minimum flow throughput. Given its large scale and combinatorial complexity, we follow a decomposition approach using column generation to solve the problem. We also develop one heuristic based on simulated annealing for solving efficiently the pricing subproblem. Our results indicate that SIC benefits strongly depend on the strength of the received signals. We show that transmission links with fixed higher data rates do not necessarily yield higher SIC gains because higher transmission rates results in sparser network topologies and thus less flexible routing. Larger networks with SIC capabilitities and bitrate adaptation however are most effective in controlling the interference and improving the spatial reuse and thus reaping the largest benefits.