On the reduction of interference effect using power control for device-to-device communication underlying cellular communication network

Device-to-Device (D2D) communication has currently been emerging as a promising technology to increase capacity and to extend coverage area in cellular communication network. D2D communication allows direct communication between two or more devices such as mobile user equipments without any base station help as a relay. However, enabling D2D features in cellular communication network will reveal more complex interference problems, because D2D communication could share the same frequency resources as its underlain cellular communication network. This paper analyzes the interference problems in such D2D communications underlying cellular communication network for downlink transmission. This paper explores the use of power control methods to reduce the effect of interference. The decision whether to increase or to decrease the power level on base station (evolved Node B/eNB in Fourth Generation/4G Cellular Networks) or on the transmitter of D2D pair (Transmitter of D2D User Equipment/TUE) is based on the estimated current Signal to Interference plus Noise Ratio (SINR). First method of power control (PC-1) uses a fixed value to control the power level of the transmitter. Another one (PC-2) uses moving average of interference power values. The simulation was carried out to evaluate those two power control methods and its results in term of Cumulative Distribution Function (CDF) of SINR are compared to the system without power control method. The simulation results show that both power control methods contribute the improvement of performances; for one cellular equipment (CUE) and 100 pairs of D2D it achieved the improvement of SINR distribution at 5% with PC-1 and at 4% with PC-2 compared to the system without powr control, meanwhile for 1 D2D pair and 100 CUEs the CDF of SINR at 0 dB achieves 40%, 3%, and 0% for the systems without power control, with PC-1, and PC-2 methods, accordingly.