Uwb Pulse Waveform Design And Modulation Study

In recent years, the rapid development of wireless communication technology and its successful application in business have deeply affected our daily lives. In order to meet consumers'need for a larger capacity, faster response and more secure wireless communication service, a new and enhanced technology should be explored at the limited radio spectrum resources. Ultra-wideband technology, by allowing the new business with current wireless communication systems coexist, provides a very promising solution for the nearly depleted resources of the wireless spectrum.The essential fundamental difference between ultra-wideband communication technology and other communication technologies is whether a very narrow pulse is used between the transmitter and receiver. By utilizing a short-duration pulse signal as its information carrier, a number of advantages can be acquired, such as a very wide bandwidth, large throughput, high privacy, robust to interference, wonderful compatibility with existing wireless business. Due to its unique characteristic, ultra-wideband technique can be widely used in consumer electronics, personal computers, peripherals, wireless LAN, as well as smart phones and other mass-market application. Considering its broad application prospects, this paper studied the modulation techniques based on ultra-wideband. This paper's contents are organized as follows:After studying some basic principles of the IR-UWB (Impulse Response-Ultra Wideband), analyzing some common characteristics of ultra-wideband pulse signal, ultra-wideband chirp signals and related theory were introduced in detail. In the ultra-wideband radio systems, the narrow pulses play the role of information carriers. The waveform of the narrow pulse has a significant impact on antenna designing, multiple access and modulation technologies of the entire system. On the basis of studying the characteristics of the pulse waveform, algorithms of the spectra matching between the pulse frequency spectra and the FCC's emission requirement were analyzed firstly, then a new method and the performance simulation was presented.The chirp UWB modulation techniques were researched. After researching the binary orthogonal keying modulation, a system model was established and then the spectrum of the chirp signal and transmission characteristics of the system were simulated; New modulation method which can cooperate with the high-order QAM modulation techniques was raised and its theoretical analysis and simulation were presented. Techniques in order to improve the modulation efficiency such as time domain overlapping and windowing were discussed. Through theoretical analysis and simulation, the paper found that the sub-carriers are mutually orthogonal under certain conditions. The Rake receiver technique and the multiple user access technique, which can be applied to the UWB systems, were briefly discussed at the end of this paper.