In an Ultra-WideBand (UWB) Low-Rate (LR) Wireless Personal Area Network (WPAN) application low-cost, low-power and low-complexity systems are expected to meet the requirements of the typical applications. These demands can only be satisfied by simple modulation schemes and easy to implement noncoherent receiver configurations. However performed field tests showed that the noise performance of such systems is quite poor. Therefore noise performance improvement is a must. This paper investigates and compares the Transmitted Reference (TR) modulation scheme with autocorrelation receiver, the On-Off Keying- (OOK) and the Pulse Position Modulation (PPM) schemes with energy detector for UWB impulse radio (IR) systems. The contribution provides an efficient method for the improvement of the noise performance of the UWB IR systems by matching the parameters of the receiver to the UWB pulse. Using this technique almost 8-dB noise performance improvement can be achieved. The Bit Error Rate (BER) of the three systems will be compared and an analytical expression will be provided for the estimation of the BER of each system.