Characteristics Test And Modeling Of Broadband Powerline Channel Based On Streetlight

The use of streetlight line to achieve broadband power line communication can effectively solve the problem of public network communication access.Studying the channel characteristics and modeling technology of streetlight line is of great significance for taking effective measures at the physical layer,fully exploiting the capacity of streetlight line communication systems,optimizing system performance,and realizing high-speed broadband communication on streetlight line.The main work of the thesis is as follows:Firstly,the input impedance characteristics,transmission attenuation characteristics,noise characteristics of the streetlight line under different states are studied.The frequency selective characteristics in the frequency domain,the time-varying characteristics in the time domain and the periodic characteristics of the changes with the power frequency signals are analyzed separately.Then,the communication performance test was carried out by using the existing high-speed power line communication equipment,and the actual communication carrying capacity of the streetlight line was analyzed.In order to eliminate the influence of the coupler on the test,the transmission characteristics an d input impedance characteristics of the power line communication coupler are studied.Finally,two power line modeling methods are studied for streetlight line.According to the structural characteristics of streetlight line,a channel model of streetlight line based on transmission line theory is established.The model generates corresponding channels according to the research scene,and analyzes the influence of streetlight line length,number of branches,branch length,and branch position on channel transmission characteristics.Based on the measured data,the corresponding multipath transmission channel model is established.The test data is fitted by a simplified multipath model.The results show that the model has a good description ability for the streetlight line channel.A piecewise fitting method based on least squares method is proposed to improve the precision of fitting and the efficiency of program operation.