Study On The Propagation Of UWB Signals And UWB-IR System Performance In A Typical Indoor Environment

Ultra-wideband (UWB) communication is the most competitive high-speed short-range wireless communication technology. The successful design of UWB communication system relies on, to a large extent, the knowledge of the UWB channel characteristics. The study on the propagation of UWB signals forms basis to simulate the UWB channels. In this dissertation, the propagation characteristics of UWB signals in a typical indoor environment for UWB Impulse Radio (UWB-IR) system is discussed, the channel characteristics and the performance of UWB-IR system are further studied.In chapter III, by using rays tracing method, the propagation characteristics of UWB signals in an empty room is studied, in consideration of the reflection from walls and path loss in propagation. The received waveforms are analyzed when the walls are set to be perfect conductor and real construction material respectively.Then, the diffraction characteristics of UWB signals in a typical office environment with a partition board is analyzed using frequency-domain analytical method for diffraction fields and TD-UTD method. According to numerical results obtained by using the above two methods, the advantages and disadvantages of the two methods are indicated. It is shown that TD-UTD method is more effective.Finally, based on the results of ray tracing method for the reflection analysis and TD-UTD method for edge diffraction analysis, the channel model of indoor UWB-IR system is primarily studied. In an ideal indoor environment with no partition board, the signal quality function is introduced to discuss the anti-multipath performance of the UWB signals. The influences of the pulse waveforms, duration of UWB signals and the building material on the UWB-IR performance are investigated in detail. In a typical office environment with a partition board, the bit error rate (BER) of the indoor UWB-IR system is calculated, and the maximal communication data rate is evaluated. The BER of the indoor UWB-IR system with different signal waveforms is compared. It is shown that the performance of UWB-IR system with two-step Gauss signal waveform is best.