In this paper, we consider a simple relay network consisting of a source, an energy constrained decode-and-forward (DF) relay and a destination. The relay is assumed to harvest energy from radio frequency (RF) signals with a time splitting (TS) based energy harvesting (EH) architecture. The relay harvests energy from the source signal as well as from the interfering RF signal. A continuous time energy harvesting method is used where the relay harvests energy for a fraction of the total block time and the remaining time is used for information transmission. The harvested energy, in case of a linear EH model, increases linearly with increase in input power whereas in case of a nonlinear EH model it attains a maximum value and then gives diminishing returns with further increments in the input power. Therefore, the EH efficiency exhibits nonlinearity due to varying conversion efficiency for different input power. In this paper, we investigated the optimal value of the harvesting parameter by incorporating nonlinearity of EH circuit and the presence of the interfering signal. The performance is measured in terms of throughput of the DF relay network and the impact on it of different parameters e.g., interfering signal, noise variance at the relay, and nonlinearity of EH circuit. A MATLAB based simulation is performed to assess the performance.