Uwb Pulse Signal Modulation Power Spectral Density In Matlab Simulation

Wireless connection eases the mobility life. Consumers are now having massive demands of this mobility in digital-electronic home. PCs, DVs, MP3 players, PDAs, Cell phones are now able to be connected by Wireless Personal Area Network (WPAN). However, WLAN and WPAN are capable to provide sufficient bandwidth for mass consumer electronics devices in future. This requires new technology to fulfill the demand of high speed WPAN. The wireless network designed for PCs now, such as Wi-Fi and Bluetooth, are not optimized for the high-bandwidth, short-distance mode. Wi-Fi reaches up to 54Mbps but it not optimized for consumer electronics including high power consumption and low bandwidth. When consumer electronics devices are connected in short distance WPAN, the technology need support high digital rate, low power consumption, low cost, small package.New technology, Ultra Wide Bandwidth (UWB) will provide the best solution.The thesis is composed of six chapters and focus on simulation of basic UWB impulsive signals. Chapter 1 introduces the potential application and characters of UWB. Chapter 2 quotes the definition of UWB signals by FCC, namely B_f≥0.2 or f_H -f_L≥500(MHz). It also gives the limitation of Equivalent Isotropically Radiated Power (EIRP) by FCC. Chapter 3 introduces the basic principle of UWB signals modulation including impulse signal waveform, impulsive composition (concepts of symbol, frame, chip), data modulation methods (PAM, OOK, PPM, PSM) and spread spectrum methods (TH, DS) as fundament of simulation in the three chapters following. Chapter 4 is the beginning of simulation. It generates waveforms of 1 to 15 derivatives of Gaussian in time domain and frequency domain. It also discusses the impact in frequency of a factor (width) and compares with theory. Chapter 5 uses the waveforms generated in Chapter 4 to generates a sequence of Gaussian impulses. By adding TH-PPM and DS-PAM modulations it generates modulized USB signals in time domain. Chapter 6 converts the UWB signals in Chapter 5 to frequency domain and compares the Power Spectral Density (PSD) with and without spread spectrum and compares with theory. Chapter 7 is conclusion.