Measurement Data Analysis And Model Simulation For Indoor And Outdoor Environment At 5.9 GHz

Wireless channel performance will directly affect the efficiency and accuracy of the received information,so that the quality of wireless communication system will be closely linked with the transmission characteristic of the wireless channel.The information such as small scale fading characteristics and large scale fading characteristics are considered as important parameters for the design of the wireless communication system.Now the research for 5.9 GHZ frequency band mainly about the communication and interconnection between the mobile cars or the information exchange between the cars and roadside infrastructure,and the research contents of this article is the wireless channel characteristic according to the measurement data,through which we can have a more comprehensive understanding of this spectrum.The main research contents are as follows:(1)The calibration experiment has been carried out for the measurement data.After the theory analysis of the calibration experiment,the calibration parameters have been obtained through both of time and frequency domain,so is the recovered data.At the same time,the analysis in time domain is considered more accuracy than the frequency domain.(2)For indoor environment,small scale fading and large scale fading have been analyzed.The aspect of small scale fading mainly about the time delay domain caused by the multipath dispersion.Through the analysis of the measurement data,some important information have been obtained,such as the probability function and cumulative distribution function of mean delay and RMS delay spread respectively.The aspect of large scale fading was analyzed by comparing the data predicted by four classic indoor model with the measurement data,finally through two kinds of criterion: the minimum root mean square and grey relational analysis,the best model has been selected.(3)For outdoor environment,there are three parts which have been researched:time delay domain 、 large scale fading and Doppler shift analysis.For time delaydomain,the statistical information of some parameters are presented.In the processing of large scale fading analysis,the influence of high rise building has been taking into consideration and the results show that the influence can be ignored.Finally the best model has been selected through two criterions which are same with the indoor environment.The third part is the Doppler frequency shift,through the maximum Doppler frequency shift,the maximum velocity of the transmitting antenna can be obtained,and the range of which is consistent with actual measurement speed.The research show that more accuracy information about the large scale fading can be obtained through the calibration experiment.Through the analysis of indoor and outdoor measurement data,the parameters of actual environment at 5.9GHz have been obtained.Such as the parameter information in delay domain can be used to help the design of system which can resist the inter-symbol interference.And the optimal model selected from the large scale fading analysis can be used to analysis the channel parameters for other environment,what's more,the predicted path loss value from the optimal model can be used for the evaluation of signal coverage.