Performance of different power control schemes for a hybrid LTE system with channel impairment

With the rapid increase in the use of smartphones and data traffic load on the base stations increasing everyday, an alternative mode of communication is the need of the hour. Device-to-device (D2D) communication allows devices to connect to each other directly without the intervention of the base station. Besides, it provides high spectrum efficiency and a much better signal-to-interference-plus-noise ratio (SINR) performance as compared to cellular communication. However, it may generate significant interference to cellular users when the same resources are shared by both the systems. Resource scheduling and power control are two key measures to deal with the interference between cellular and D2D user equipment (UE). In this paper, we have focused mainly on power control in D2D communication. The main objective is to study the impact of channel imperfections like multipath fading and shadowing on different power control schemes. The system consisting of a D2D pair incorporated into an Orthogonal Frequency Division Multiple Access (OFDMA) cellular system is simulated for different combinations of power control schemes for cellular and D2D users. The variations in SINR performance of the system, when fading and shadowing are introduced in the channel along with pathloss, illustrates the effect of these parameters on the Long Term Evolution (LTE) power control schemes. Also the change in outage probability has been investigated by adding more D2D pairs to the system so that it resembles a D2D communication system in realtime scenario.