Wideband Wireless Channel Propagation Characteristics Modeling Based On Measurement

With the development of communication technology and the wider spread of mobile handheld terminals,the requirements of mobile wireless data service are increasing from users,which continuously demands for better data rate and spectral efficiency.3.35 GHz,4.9 GHz and 5.4 GHz are three potential spectrums for 5G mobile communication service in China.Therefore it’s essential to perform channel measurement and mod-eling for those frequencies in typical application scenarios in China.This thesis performed channel measurement in four locations in Bei-jing and Xi,an,which are under urban marco cell(UMa)and suburban marco cell(SMa).The channel propagation characteristics including path loss and delay spread of 3.35 GHz,4.9 GHz and 5.4 GHz have been ob-tained based on statistical analysis of channel impulse responses(CIRs).The work of this thesis can be categorized into two parts:1)The channel measurement system was developed based on the theory of spread spectrum sliding correlation method.Four main channel measurement methods are discussed and the spread spectrum correlation method is chosen for its feature of increasing the time bandwidth product.The Agilent E4438C signal generator and Tektronix RSA 6114A spectrum analyzer are the core parts of the measurement system with the amplifier,antennas and so on.M-sequence is chosen as the transmit signal.The spectrum analyzer is controlled by PC with labview program at the re-ceiver side,which can configure the parameters such as the interval of sampling.Data post-processing program was developed and can be used in other similar projects.2)Under UMa and SMa scenarios,channel measurement was car-ried out in Beijing and Xi’an.The channel parameters are obtained from the CIRs.The path loss models for every measurement locations are pre-sented categorized into LOS and NLOS conditions.The free-space model and ITU-R M.2135 model are used as references.The path loss exponents of the derived models are close to the M.2135 model.Because the LOS environment defined in this thesis is more like the OLOS environment,the derived path loss model has certain difference with corresponding M.2135 model in the LOS environment,and the two models are pretty close in the NLOS environment.As the vegetation is dense in the SMa scenarios,the path loss exponents of the LOS environments in SMa are a bit greater than that in UMa.In the NLOS environment,path loss expo-nents are all in the range of 3.2 to 3.8 for both scenarios.The mean delay and root-mean-square(rms)delay spread are obtained from the power delay profile.The rms delay spread is smaller in SMa than that in UMa.As the frequency is increased,the rms delay spread is decreased in most measurement results in UMa.All the probability distribution functions of the rms delay spread are fitted by the Log-Normal distribution.The path loss and delay spread characteristics of 3.35 GHz,4.9 GHz and 5.4 GHz are studied in outdoor mobile communication scenarios in this thesis.The work can be reference for the research of multiple service coexistence in 5G spectrum and the design of wireless mobile communi-cation network.