Spectral Efficiency Enhancement Using Multiaccess Scheme in Heterogeneous Network

In this paper, we propose a spectral efficiency enhancement algorithm through simultaneous accesses to heterogeneous networks, where a mobile station (MS) can simultaneously access different non-interfering networks with different radio access technologies (RATs). This simultaneous access (i.e., RAT diversity) is determined in terms of the distributed optimal solution, which implies that MSs can decide whether they connect with multiple RATs or not. To derive the optimal solution, we first show the advantages of multiaccess (MA) by an example in heterogeneous networks, and analyze the spectral efficiency of MA in multi-RAT system. Through our analysis and simulations, it is shown that the proposed algorithm is able to achieve the increase of spectral efficiency compare with vertical handoff (VHO) method, which selects only one network having the best channel quality. As a result, the proposed MA algorithm can be considered as a viable solution to get more spectral efficiency in heterogeneous environments.