Deli Liu

The sub-channel allocation algorithm in femtocell networks based on Ant Colony Optimization

Femtocell is an effective technology to improve the system performance. In this paper, we address the problem of sub-channels allocation in OFDMA two-tier femtocell networks. Our objective is to maximize the rate sum of multiple femtocells with consideration of cross-tier interference between macrocell and multiple femtocells. A resource optimization approach based on Ant Colony Optimization Algorithm is proposed to implement the solution process of system. Simulation results show that the proposed algorithms not only improve the capacity of the femtocell system but also provide good proportional fairness among the femtocell users, as compared with the traditional algorithm.

Improved performance analysis based on a novel hybrid access algorithm in femtocell networks

As the most potential way to improve the overall performance of the next generation wireless networks, femtocell has attracted much attention from vendors. To femtocell, hybrid access mode is a comprise access mode that operates between close access mode and open access mode. With this kind of access mode, not only the pre-registered users are able to access it, un-registered users could also gain benefits as long as there is available resources. In this paper, we propose a novel access control algorithm based on hybrid access mode. Simulation results show that this algorithm can decrease the outage rate of macro users without causing too much signaling overhead.