SOFT FREQUENCY REUSE FOR MILIGATION OF INTERCELLULER INTEREFERENCE

Background. The appearance of femtocells in LTE networks has provided indoor coverage and overcome large data flows for operators. However, strong interference occurs in neighbouring femtocell users due to the limited available spectrum in cellular networks that transmit data in the same radio range. In densely deployed environments, interference issues in single-channel femtocells cause significant performance degradation. In this study, we mitigate inter-cell interference in femtocell networks by combining femtocells as a result of common interference and soft frequency reuse in downlink and uplink by moving and exchanging interfering physical blocks. 
Objective. The purpose of the paper is to improve the efficiency of ensuring the quality of services in wireless networks by reducing any interference due to the distribution of traffic, which is able to provide uninterrupted connection to the user. 
Methods. Enabling conditions for inter-cell interference mitigation in LTE-based femtocell networks with soft frequency reuse. 
Results. Interference is a key issue in the deployment of LTE femtocells. Closely located femtocells interfere with each other if they transmit on the same frequency. Therefore, crossing femtocells and enabling them to allocate resources and reuse soft frequencies effectively reduces interference and prevents the loss of network resources. The scheme is triggered whenever the user's femto equipment experiences strong interference from neighbouring femtocells. By assigning a separate set of physical resource blocks to users at the edge of the cell, our scheme significantly reduces interference, which automatically increases cell throughput. The simulation results show the advantages of applying our scheme, in particular, the interference of the user's femto-equipment is reduced by 14% and the throughput is improved by 25%. That is, we observe a significant improvement in the performance of femtocells. 
Conclusions. A femtocell crossing scheme with soft frequency reuse is presented to reduce interference between femtocells of LTE networks, which allows effectively ensuring the quality of service transmission in wireless networks by reducing interference and increasing performance through traffic distribution.