Interference Management Using Power Control for Uplink Transmission in Femtocell-Macrocell Cellular Communication Network

Femtocell is a small cell of 10-30 meters radius deployed in the existing larger cell (macrocell) forming two-tier femtocell-macrocell cellular network. However, the deployment of femtocell into the existing macrocell cellular network is facing more complex interference problems. This paper focuses on interference management using power control methods for the uplink transmission of such two-tier cellular networks. Types of interferences considered in this paper are co-tier (femtocell-to-femtocell and macrocell-to-macrocell), cross-tier (femtocell-to-macrocell and macrocell-to-femtocell), and total interferences. This paper considers multi-cell scenario of cellular communication network consisting of three macrocell cellular networks in which each macrocell is deployed 10 femtocells. This paper analyzes one of three macrocells on the uplink transmission with the other two macrocells on downlink transmissions. All femtocells are on the same transmission conditions as its co-located macrocells. This paper observes one of ten uplink femtocells on the observed uplink macrocell. Through simulation, this paper firstly analyzes co-tier, cross-tier, and total interferences for the system without power control. The results of Signal to Interference plus Noise Ratio (SINR) in term of its Cumulative Distribution Function (CDF) for the system without power control are used as a baseline system. Then, this paper proposes the use of two power controls namely PC-1 and PC-2 in this paper which both power controls work based on the estimated current SINR. Both power control methods are also to make sure that the transmitting power of the users in the observed base stations (eNB/HeNB in 4G cellular network terminology) will not exceed maximum or minimum of its allowed transmitting power (uplink transmission case). The simulation has been carried out and the SINR results were collected and compared to baseline system. The simulation results show that PC-1 and PC-2 outperform the baseline system in terms of CDF of SINR.