Opportunistic Open-Access Macro-Femto Networks with Femto Base Station Selection

We consider an open-access macrocell-femtocell spectrum-sharing network with multiple femto base stations (FBSs) that are available to opportunistically handle the nearby macro users (MUs) traffic in order to manage the amount of co-channel interference to/from macro and femto systems. In fact, we believe that the co-channel interference can be managed by allowing strong macro interferers to communicate with nearby femtos. In this context, while multiple femtos are available in the area, one important question is: Which femto must be selected to serve the strong MU in order to more efficiently control the co-channel interference? In this regard, we assume that the MU of interest is located near a given number of femtos. Making use of this availability, we investigate a framework for establishing communication between the macro base station (MBS) and the MU of interest via the femto network while considering an appropriate constraint on the interference received at the neighboring MU. Then, we propose utilizing two major selection schemes, namely, \emph{partial} and \emph{reactive} selections, to find the appropriate FBS that can better match the femto capacity limitations. We also investigate the average bit error probability of the proposed system for both mentioned selection strategies. Finally, illustrative numerical results are shown and the benefits of using cooperative transmission with different selection strategies are discussed.