Research On UWB Coexistence With Mobile Communication System And Waveform Design

Ultra-Wideband Radio is a new radio technology, which is a major advancement in the field of wireless communications and studied in a wide range in the world. It is a promising technology in short-rage indoor wireless communication, accurate position and other great usage in the near future. The prominent feature of UWB signal is the wide-band and low power spectral density. Even though, this will interfere with the existing communication systems in some extent. Especially, when working with a number of UWB equipments, it will become a potential interference to other wireless communications.In this paper, we explain the coexistence and compatible problem of UWB systems with mobile communication system. The objective is to investigate the impact of cumulative interference from multiple UWB systems to the downlink of PHS, GSM-900, GSM-1800, TD-SCDMA. Since indoor environments are considered a three-dimensional geometry for the spatial distribution of the UWB devices is assumed. To obtain a realistic scenario, a model describing the transmission activity of the UWB devices is taken into account. 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, it has important realistic significance.Besides, waveform designing is the most feasible and effective method for the coexistence and compatible problem of UWB system with other wireless communication systems. The first and foremost task of waveform designing is to approximate FCC's spectral mask. According to many pulse shape design algorithms which meet the FCC spectral mask are researched only in 3.1～10.6GHz frequency bands with a low use efficiency of spectrum. In this paper, after the linear combination of ten normalized Gaussian Monocycle derivatives are investigated, with the software of MATLAB , a new pulse shape design algorithm is presented that is close to the FCC spectral mask between 0 to 10.6GHz frequency bands, and the use efficiency of spectrum is also greatly improved.