Dynamic base station assignment and resource allocation in MIMO CR small-cell networks

Cognitive radio (CR) is an effective technology to deal with the spectrum scarcity and improve spectrum utilization. The growing small-cell is another effective method to enhance the spectrum efficiency of wireless networks by way of the spatial reuse of frequencies. In this paper, we consider a Multiple Input Multiple Output (MIMO) CR in small-cell networks and propose an efficient algorithm joint optimize both cell selection and resource allocation, to maximize the sum rate of CR users, under the condition of interference to primary users below a certain value. CR users decide to access the channel based on the results from spectrum sensing. The influence of the sensing time is also taken into account, since the longer the sensing time the shorter the data transmission time. To deal with the non-convexity of the optimization problem, we introduce a sensing-based successive convex approximations (SSCA) algorithm to get a locally optimal solution of the non-convex problem. Simulation results show that the proposed SSCA algorithm can achieve a better performance.