In this report, we derive the performance graphs for UWB communication systems using different combining techniques in a RAKE Receiver. Comparisons have also been made between the techniques and conclusions have been drawn based on the requirements. We also incorporate the effect of number of fingers on the performance of the receivers. The results obtained give us way to evaluate the performance of Rake reception of UWB signals in dense multipath channels. We present simulation results using IEEE 802.15.3a UWB channel models. We evaluate the performances of Rake Receivers with different pulse-widths and also the effect of inter-frame interference.