On The Radio Propagation Channels Of Broadband Multiple Antenna System: Characteristics, Measurements And Models

The dissertation studies the characteristics, measurement and modeling methods of broadband MIMO radio propagation channel, which principally are based on two field channel-measurement campaigns in 2005 and 2006 respectively. Space-alternating Generalized Expectation-Maximization algorithm (SAGE) is picked for the parameter estimation. Two broadband MIMO channel models plus a tapped-delay spread model are proposed.The acadamic background of the dissertation is elaborated primarily to accentuate the significance and necessity of motif of channel measurement and modeling study.All the ever-emerged channel measurement techniques, especially broadband MIMO channel measurement, are summarized. Measurement methods, including SISO, MIMO channel measurement, as well as the methods, requirements and scenarios of broadband MIMO channel modeling, are classified and analyzed. The structure and correlation of array as well as channel relation based on MIMO channel measurement are presented and analyzed in detail. Based on study of recent references, four simulation techniques, namely the 'Monte Carlo', the one based on DOA distribution of MIMO channel, the one based on determined correlation coefficient and frequency-domain simulation technique, are intruduced. The capacity of broadband MIMO channnel is studied. The statistic properties, including the factors fluctuating the channel capacity, are analyzed qualitatively. Subsequently the optimization method of channel capacity is proposed. The panoramic description of a broadband SIMO channel measurement is divided into two parts, measurement plan and results analysis. The former is orgnized to give the pick strategy of measurement site, parameters and items, and to introduce the measurement system while the later is assigned to report the measurement results of path loss, channel impulse response, delay spread, multipath statistic, sample-pool pick strategy, delay-time domain and frequence-time domain channel response, channel and arrays correlation.The algorithms of extracting the parameter sets of the tapped-delay line model from field meausurement of power delay profile as well as the model itself are proposed. An analysis and a simplified application of the algorithms are given hereinafter which leads to three recommended parameter sets of that model for indoor, outdoor NLoS and outdoor LoS scenarios respectively.A broadband MIMO channel measurement with 100MHz bandwidth and 50x8 MIMO array is introduced. The characteristics of MIMO radio propagation channel are analyzed both qualitatively and quantitatively. Some rules related with broadband MIMO channel are obtained. The measurement plan is presented to describe the measurement processes, measurement scenarios, and measurement system. Then the SAGE algorithm is adopted to estimate 8-dimension channel parameters in the measurement campaign. From the results of parameters estimation, the characterestics, including MIMO channel impulse response matrix, delay domain parameters, multipath parameters, angle domain parameters, channel capacity, correlation, are analyzed.Two broadband MIMO channel models, namely the polarization physical model based on measurement results and the dispersive model based on Kronecker product, are proposed with detailed generating steps. The former, by which the reconstructed transfering-function matrix and channel capacity statistic are tallied with those obtained from field meansurement, is fit for estimation system for candidate RTT. Three recommended parameter sets of the model for indoor NLoS, indoor LoS, and outdoor scenarios respectively, extracted from field results, are nominated and itemized. The later can be applied extensively to several scenarios, such as SISO/SMO/MIMO, indoor/outdoor, narrowband/ wideband and performs well in description of pinhole channel. Simulation results and explanations of both models are presented whereafter.