Channel reallocation for reducing power consumption in femtocell mobile networks

摘要

Future mobile networks are known to deploy a two-tier architecture of macrocell - femtocell [1]. In the two-tier architecture, femtocell downlink channels can cause strong co-channel interference to downlink transmission of macrocell users (MUs) which use the same frequency. The co-channel downlink interference to the MU might cause the MU's QoS degradation. To maintain the QoS of the MU's connection, the serving macro base station (MBS) has to increase the transmission power of the macrocell downlink. The power increment will also cause more co-channel interference to other MUs of the neighbor MBSs thus results in increasing downlink transmission power of the macrocell subsystem. In this paper, we analyze the co-channel downlink interference and then propose downlink channel reallocation schemes, denoted as MBS-sensing and CFAP-sensing schemes, in order to reduce the power consumption of the macrocell subsystem. Simulation results prove that using channel reallocation schemes provide much better downlink power consumption efficiency than the case when the channel reallocation is not deployed. In general, the CFAP-sensing scheme has better performance than the MBS-sensing scheme. However, when femtocells have long coverage radius, the MBS-sensing scheme is the better solution because it is less complex and has similar performance.