A study of ultrawideband techniques for wireless communication.

摘要

The modern world has become more reliant on technology for advances in communications, entertainment, manufacturing, security, etc. With such a rapid proliferation of electronics and the advancing idea of true global communications brought on by the Internet, a desire for more and more devices to communicate with each other has grown increasingly important. For decades, physical cables were used to provide that connection to exchange signals between devices using wiring made from aluminum, copper, glass and plastic, among others. But as the amount of electronic devices rises, so do the number of cables to connect them to each other. The situation is similar to the birth of the integrated circuit. As the number of discrete components in designs increased, the amount of time necessary to wire up these large circuits began to pose a problem. The answer was the invention of integrated circuits, packing tiny transistors together onto a single chip, and its advancements in technology have allowed for the number of transistors to double every 18 months, according to Moore's Law. Data communications technology has reached a point where it can utilize perhaps the most difficult medium possible, air, bringing the idea of a world without wires, a wireless world, to the forefront.; Wireless electronic communications serves as a solution to the problem, yet creates hurdles of its own. As the number and types of wireless systems in use continue to grow, coexistence with existing systems and future technologies becomes extremely important. Ultrawideband, or UWB, is a wireless technology promising to deliver high speed, short-range wireless communications over a very wide bandwidth at power levels low enough to avoid interference with existing wireless systems but still provide a reliable link. It should not be thought of as a simple cable replacement solution. Ultrawideband has the potential to create a platform of convergent wireless protocols built around its technology.; This thesis provides a brief introduction to wireless communications and its progression toward ultrawideband. The concept of channel modeling and modifications that need to be made for ultrawideband are discussed. A synopsis of the physical layer and medium access control sublayer specifications for the WiMedia Alliance's MultiBand Orthogonal Frequency Division Multiplexing version of UWB is made, including detailed descriptions of the different types of channel coding used. Finally, ultrawideband's struggles within regulations and standards bodies are described, along with a discussion of ultrawideband's wireless competitors.