Uplink Power Control Method for LTE Femtocells Based on Resource Usage Aggregation

In LTE, uplink (UL) transmit power control is important to mitigate the UL aggregate interference from all femtocells to the macrocell, which is increased as the number of femtocells is increased. We propose an UL power control method for LTE femtocells adaptively setting target received power by using the aggregation of the resource usage of femtocells. With this method, when the aggregate resource usage is small, the UL throughput of femtocells is improved by increasing the UL transmit power. When the aggregate resource usage is large, the UL throughput of macrocells is maintained by decreasing the UL transmit power. With LTE system level simulations, it is shown that while in the full buffer traffic condition the decline in the UL throughput of macrocells due to introducing femtocells was suppressed, in the FTP traffic condition the UL throughput of femtocells was improved by 24% at the largest in comparison with the method using the number of active HeNBs.