Interference Management with Relay-Based Clustering Method on Ultra Dense Networks of Femto-Macrocellular Network

Ultra Dense Networks (UDN) which is one of the key technologies for 5th Generation (5G) Cellular Networks is intended to increase the capacity and coverage of the cellular networks. Densely deployment of femtocells in UDN mitigates signal attenuations experienced by indoor users, but potentially increases co-tier and cross-tier interferences as the consequence of spectrum sharing with other femtocells and its associated macrocells. The interference problems in such network become worst when the femtocells are located on the cell edge of its macrocells. In this paper, we design interference management of femtocells located in the cell edge of macrocell area for uplink transmissions. We propose interference management to reduce the interference effects of the femtocells located in the cell edge area of macrocell using a relay-based clustering method. The simulation results show that the proposed method (relay-based clustering) can improve SINR and system throughput compared to the conventional system, i.e., the system without relay-based clustering. We applied the sectored macrocell on the observed macrocell having 6 sectors in the simulation experiments. When we are targeting the SINR value of 20 dB, the SINR value is below 20 dB for conventional systems in sectors 1 and 2 are 86% and 87 %, respectively. However, the probability of the SINR in a system using the relay-based clustering method that does not reach the target in both sectors 1 and 2 are 71% and 74% correspondingly. These results are in line with the expectation that the relay-based clustering method can improve the performance of femtocells in the cell edge area.