Research On UWB Communication Technologies And Algorithm

Recently, it presents PAN in area of short-range wireless communication. Instead of using cables, PAN uses radio or infrared to build up information network. Technologies to realize PAN have buletooth, IrDA, Home RF and UWB. Compared with others, UWB's high performance and low power make it competitive. UWB has such advantages: high data rate, low spectrum density, high precision location identification and inherently exceptional multi-path immunity, so it can become the crucial technology of future short-range wireless communication and accessing computer network, it has become the research focus in the wireless communication field.This paper research about UWB's key technologies, including pulse design, multi-user detection, code and decode, interference of UWB devices to mobile communication terminators.In order to coexist with existing communication systems, FCC regulates strictly on UWB's spectrum density. In UWB radio, Gaussian pulse use widely, it characterizes UWB wireless pulse and it can realize easily, but in cannot satisfy with FCC's regulation. Some researchers present some improved methods, but these are complicated. This paper present pulse design based on different Gauss and derivatives, it makes spectrum approximate standard and increase spectrum efficiency.In multi-access communication system, due to various reasons, MUI can affect the system. There are two main multi-access, one is THMA and the other is DS-UWB. For THMA, we use the specific properties of TH sequences and present a reduced complexity multi-user detection, then we improved it and the performance gets better. For DS-UWB, we present a multi-user detection with pretreater, the pretreater mentioned in this paper can calculate most user information sequences by low computational complexity and assure that the results obtained from pretreater are the same as that of optimum multiuser detection. Since the user information sequences obtained from pretreater have been global optimization, we can reduce them from original multi-user detector and then a relative small scale multi-user detector can be obtained. Compared with the original one, the multi-access interference of small scale multi-user detector is reduced. As a result, we can solve this small scale multi-user detection by some common multi-user detector.In order to improve system's performance, we can combine UWB with encode. Because UWB is a high data rate system, the encode project should be low rate and the codeword after encode should be short. This paper present semi-determinative initial state convolutional coding and decoding algorithm. This algorithm perfectly deals with the conflict between the performance of coding and the codeword after coding length after coding. Being sure of the codeword length, its performance approximated its optimum performance, making it a pragmatic coding and decoding algorithm.For the impact of cumulative interference from multiple UWB devices to mobile communication devices, we consider a three-dimensional geometry for the spatial distribution of the UWB devices. The outcome of this study is a statistical model, i.e. a probability density function (PDF). With this model, the maximum interference from multiple UWB devices, the maximum acceptable UWB-device density, the minimum distance between UWB devices and receiver are derived in different link budget degradation.In conclusion, we study key technologies of UWB, and new models and algorithms had been proposed, simulations and experiments had tested that the models and algorithms can get good results.