Joint uplink and downlink optimal mobile association in a wireless heterogeneous network

Many technologies ranging from advanced physical layer antenna transmission schemes to efficient air-interface resource management schemes have been developed for spectrum efficiency improvement for the future wireless networks. However, most of these technologies quickly reach their theoretical limits without much room for further improvement. In order to meet capacity demands from the explosive data traffic growth, heterogeneous networks with base stations of diverse coverage and transmission powers are expected to achieve a high spectral and energy efficiency. Compared to the traditional homogeneous networks, issues such as mobile association, load balancing and interference coordination need to be studied carefully in order to realize the performance gain in a wireless heterogeneous network. In this paper, we propose a new mobile association scheme that jointly maximizes downlink system capacity and minimizes the mobile station (MS) uplink transmitting power. Simulation results show that a significant performance gain on the defined objective function is achieved.