Routing and resource allocation with collision constraint in multi-hop cognitive radio networks

In this paper, we study the routing and resource allocation problem in multi-hop cognitive radio networks. The collision between primary users (PUs) and secondary users (SUs) is taken into consideration, which is unavoidable if activities of PUs and SUs are not synchronized with each other. Our objective is to maximize the average throughput of a secondary traffic flow while the number of collisions is restricted to be less than a predefined threshold. Aiming at this, a proper routing path is selected according to its longtime achievable throughput performance, and then radio resource on the selected path is allocated to get a high throughput. A routing path selection algorithm is proposed which expands the paths hop by hop and discards unnecessary paths. The resource allocation problem is formulated to an optimization problem with aforementioned objective and restriction. A low-complexity heuristic algorithm is proposed to solve the problem. Simulation results show that the proposed method is effective and can achieve the performance similar to the optimal solution.