This Book demonstrates the basics UWB technology, and explains why it is a better candidate compared to most of the existing technologies in short-range high-speed communications, and then discusses the UWB transceiver system architecture, and shows the transmission characteristics and the Pulse shapes used for UWB communications. Moreover, the Book studies the utilization of a new UWB pulse shape which is the 6th derivative Gaussian pulse and its performance using two major multiple access schemes used in UWB Communications; Direct-Sequence UWB (DS-UWB) and Time-Hopping UWB using Pulse-Position-Modulation technique (TH-PPM UWB), along with their data modulation methods. Finally, this Book demonstrates the design and operation characteristics of also two major reception techniques used in wireless communications generally and in UWB communications specifically; the Rake-receiver, and the Minimum-Mean Square-Error Receiver (MMSE receiver), more explicitly the Book concerns about the MMSE receiver because its algorithm uses Adaptive filtering scheme with is very important and helpful for detecting the UWB signals in the Multipath Fading channels suggested in the Book.