SINR Model with Enhanced Direct Sequence Spread Spectrum (EDSSS) Method in LTE-Wi-Fi Integrated Networks

Wireless Fidelity (Wi-Fi) has been introduced in Third Group Partnership Project (3GPP) Release 12 as an alternative solution for offloading high traffic in LTE network. In addition, Wi-Fi has many advantages such as low operation cost, easy-installed systems and it is currently widely implemented in houses and offices. However, a phenomenon called co-channel interference may occur within LTE-Wi-Fi networks because of its low power transmission when compared to the macrocell. Hence, Wi-Fi users may suffer worst network degradation at frequency 2.4GHz due to its collision with LTE band 40. In order to solve this network issue, an interference management is needed as it affects users perceive experiences and services when using LTE-Wi-Fi integrated networks. In this paper, a method known as Pulse-Shaping Algorithm (PSA) has been integrated with Direct Sequence Spread Spectrum (DSSS) which is called Enhanced Direct Sequence Spread Spectrum (EDSSS) to model Signal-to-Interference-Noise Ratio (SINR). The introduction of this method is for reducing the occurrence of co-channel interference. Furthermore, a new coefficient named as a radius fraction (β) has been introduced in order to evaluate the SINR expression for User Equipments (UEs) in LTE-Wi-Fi networks. The simulation results discovered that β-coefficient with value of 0.2 has given the most optimum improvement of SINR for LTE and Wi-Fi users. By modifying the SINR expression with PSA method, the network performances for users have improved significantly.