QoS based Joint Radio Resource Allocation for Multi-Homing Calls in Heterogeneous Wireless Access Network

In this paper, we propose QoS based radio resource allocation, where multi modal users are capable to connect to multi-RATs in heterogeneous wireless access network (HWAN). Our optimization problem is based on system sum-rate maximization under the QoS constraint. We propose a joint radio resource allocation scheme where we use Lagrange duality and dual update method to find a solution for the optimal allocation of subcarrier and power in OFDMA system and optimal time share in WLAN system. Numerical results show that the overall sum-throughput of our proposed optimal resource allocation algorithm in HWAN for multi-RAT approach outperforms the single RAT approach that uses WLAN or OFDMA based system. Furthermore, we analyze the impact of minimum data rate requirement of mobile users on the convergence rate of our proposed algorithm. Matlab based simulation results show that convergence rate of our propose algorithm is independent of the minimum data rate requirement of users.