Ultra-Wideband Channel Modeling In Offshore Oil Platform Environment

Since dispersed Production sites,complicated production environment, wireless sensor network is suitable for data communication in oil industrial. UWB has the advantage of high transport rate, low power consumption, high security, it can be used in physical layer to improve the performance of the network. To investigate UWB system, characteristic of UWB signal transmission and channel should be researched, and the reasonable channel model for the application environment should be established, Since UWB reasonable channel model relate to the environment, we need actual measurement in the application environment, and derive the needed channel model via earnest analysis of measurement data.In this thesis, we investigated and researched UWB channel modeling in offshore platform Measurement system are build according to the actual environment and measurements are done with a vector network analyzer (VNA) in the frequency band of 3-10GHz both in line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios. In view of the measurement data, channel impulse response and power delay profile were obtained by data-preprocessing via Matlab. PDP indicated that for NLOS with large distance, the maximum of the components is several tens of nanoseconds after the arrival of the first component and can be described as mixed exponential function of delay, and the multiple scatter clusters are caused by the special nature of the special environment. First, the clusters were identified by slop of the regression line. On large scale channel modeling, least square method was used to fit the distance attenuation model. On small scale channel modeling, multipath arrival rate and power decay constant were discussed the measurement data approximately can be fitted to S-V model, and some modifications are made to provide excellent fit: measurement data indicate ray power decay constants were not the same for all clusters, they depend on delay with a linear relationship, and the peak power value of each cluster didn't fit to exponential decay, while total power of 50 bins in a cluster fit to an exponential function of delay. The small-scale fading fits to m-Nakagami distribution, values of m were calculated according to m-parameter estimator, according to the frequency distribution histogram of m, m-parameter range from 0.8-1.1. At the same time, value range of mean excess delay, RMS delay spread, number of dominant multi-path are obtained. UWB channel impulse response and channel characteristic parameters are calculated according to the established model. The results indicate channel characteristic parameters calculated by model and calculated by measurement data are basically same, and multipath fading fit to the statistics of measured data, therefore the method of data analysis is correct and the model is reasonable.