Analysis of downlink power control and cooperation scheme for two‐tier heterogeneous cellular network

Abstract

SummaryThe traditional cellular network cannot keep pace with the dramatic growth in data traffic due to exponentially increasing number of multimedia applications and mobile subscribers. Recently, femto base stations (FBSs) are deployed with the macro base station (MBS) tier for off‐loading the data traffic and to improve the indoor coverage of the heterogeneous cellular network. However, FBS deployment also increases the cross‐tier interference of the heterogeneous cellular network resulting in outage performance degradation of MBS tier. This work develops an analytical framework to limit the cross‐tier interference of MBS tier using power control scheme (PCS). The proposed PCS works on path loss inversion and location‐based power level rule for FBS. Moreover, a cooperation scheme and an association policy with MBS (CSAPM) are introduced to improve the outage performance of the FBS tier. Tools from the stochastic geometry are used for deriving the signal to interference and noise ratio outage probability, total outage probability, and area spectral efficiency (ASE) of MBS tier and FBS tier. Additionally, ASE maximization problem is formulated to evaluate the optimal density of FBSs. The effectiveness of the proposed PCS and CSAPM on outage performance and ASE are numerically demonstrated. It is noted from the results that the proposed CSAPM can compensate the loss in outage performance of FBS tier due to PCS. Finally, simulation results validate the analytical results.