IR-UWB Signal Generation, Control And Detection

The Ultra-Wideband (UWB) electromagnetic pulse is one of the most important and vigorously developing research field, it is characteristic of the transient and the ultra-wideband, and has the wide prospects for application. It has attracted increasing attention owing to civil application in target identification, medicine and object detection under ground etc. It will extremely promote technological progress of these field, and it is able to develop the new type of UWB radar and communication system due to its different from normal electromagnetic signal in generating, radiation, propagating, receiving and processing etc. UWB technology has become a strong candidate for wireless personal communications (WPAN) since the Federal Communications Commission (FCC) has released the commercial use of UWB systems in 2002. Impulse Radio Ultra-wideband (IR-UWB) scheme has received more and more attention due to its low complexity, numerous subsidiary functions (such as orientation and detection) and application prospects.this paper presents thorough investigation in transient electromagnetic wave generation, its control and detection in wireless communication. By describing the narrow pulse in time-frequency analysis and Fourier analysis, we show the intrinsic properties of transient and ultra-wideband short pulses. This work set the theoretic foundation and insight in pulse shaping design and signal generation. It also offers inspiration in low cost and simple pulse detection. Further more, reliable solution can be retrieved for generating, modulating and detection signal in industrial application, propelling IR-UWB practical application.A time-frequency analysis method for short pulse is proposed. The difference and symmetry between IR-UWB signal, narrowband sinusoidal signal and other UWB realization signal is defined by this method. The key features of IR-UWB signal are the transient and low duty cycle in time domain, flat envelope and linear phase in frequency domain.A RF modulation UWB transceiver structure is proposed to generate and modulate the short pulses. pulse signal of high repetition and stability is achieved by single triggered pulse generator, with the data modulated after pulse generation. Based on time-frequency analysis, a novel method to design the waveforms of IR-UWB signals is proposed. The constructed waveforms are with raised cosine roll-off frequency spectrum and less time duration. Furthermore, series of time-domain waveforms with orthogonal properties constructed by this method can be adopted in high-level modulated UWB systems. Two kinds of pulse generation methods are proposed based on the analysis of Impulse signal. One is direct pulse generator based on step recovery diode and the other is carrier pulse generator based on tunnel diode.A receiving method adopting pulse's peak detection for IR-UWB system is proposed, which can reduce the requirement of high timing precision. To overcome the frame interference, an AGC method based on receiving duty cycle has been used. taking the pulse's characteristic of low duty cycle into account, we use multi-phase sampling clock synchronization method, to reduce the single-route sampling rate. Adopting peak detection, AGC based on receiving duty cycle and multi-phase synchronization, the method can be an optional scheme for lowering sampling rate and system realization cost.engineering methods of IR-UWB wireless systems which focus on the RF front-end of the transceiver are studied by theoretical analysis and experimental verification. Pulse generation and pulse modulation circuits based on step-recovery diode, high-speed digital logic element circuit, RF switches and high-speed mixer are proposed. Aiming at the relevant reception and peak detection of non-associated receiving, a new type of short-term gated integrator circuit and transient pulse detection circuit are proposed for short pulse reception. Finally, a design of IR-UWB wireless transmission system based on pulse peak detection is shown. High rate of 190Mbps is achieved for the first time in laboratory. The system has been verified by transmission of real-time no compression video and HDTV using USB2.0 over UWB.