In this paper, we enhance the performance of Pulse Position Modulation scheme applied with Impulse Radio Ultra WideBand transmission, while the receiver is based on non-coherent energy detection. By exploiting the time properties of Gaussian pulse derivatives, it was possible to adjust the modulation index in order to improve the data rate in compromise with the error probability. For the 5th Gaussian waveform, we succeeded in increasing the information rate by 25 % with a notable reduction in the bit error rate simultaneously. The transmission speed can be further boosted by 33 % at the cost of additional errors collected at receiver side, which depend on the signal-To-noise ratio and generated pulse dynamics.