Novel EBBDSA based Resource Allocation Technique for Interference Mitigation in 5G Heterogeneous Network

Telecom operators have applied the cell association and load balancing technique with femtocell (HeNB) in urban dense 5G Heterogeneous networks (HetNets) for reducing loads of macrocells (MeNBs) and improving the total capacity. However, this deployment creates an interference scenario; mainly, the problem occurs severely from the users of the connected and autonomous vehicle in MeNBs coverage to HeNBs coverage. The main reason is that deploying HeNBs in MeNBs applies the co-subchannels by HeNB and MeNB, leading to severe cross-tier interference (CSI) in the OFDMA subcarrier. Due to this CSI occurrence, the spectral efficiency, Signal to Interference Noise Ratio (SINR), and system outages affect severely. As a result, the MeNB User Equipment (MUEs) and HeNB User Equipment (HUEs) suffer from service disruption, and the entire system's performance degrades. This challenge has attracted the attention of many researchers and the telecom industries. As a result, several interferences controlling methods such as enhanced frequency allocation strategies, power management, control technique, resource scheduling, spectrum sharing, and Cognitive Radio (CR) techniques have been suggested for 5G communications. However, the study suggests that downlink interference is still challenging in dense urban zones, especially in multilevel and high-rise complex buildings. This paper proposes the EBBDSA-CSI technique where a novel Evolutionary Biogeography-based Dynamic Subcarrier Allocation (EBBDSA) algorithm is introduced for reducing the cross-tier Subcarriers interference (CSI) issues in MeNB and HeNB. The system-level simulation results suggest that the proposed algorithm reduces the system outage to 88.1%, and total spectral efficiency achieves 83.6% compared to the existing techniques.