Research On Channel Measurement And Modeling Method Of X-Band Based On Wireless Body Area Network

The propagation characteristics of wireless channels are crucial for improving the performance of wireless communication systems.To ensure mastery of the characteristics of wireless channels in real scenarios,this article studied the propagation characteristics of high-frequency wireless channels in typical indoor office scenarios,analyzed and modeled channel propagation characteristics parameters such as path loss,shadow fading,delay power spectrum,and root mean square delay extension through a large amount of measured data.The research results of this study can provide theoretical reference and basis for the design of the future high-frequency indoor short-range wireless communication system and the deployment of Pico cellular network.The main contents and innovations are as follows:(1)The distance path loss characteristics of X(8～12GHz)band channels in an indoor wireless body area network environment were studied.Based on a large amount of measured data,shadow effects and penetration losses in different parts of the human body were compared and analyzed.The results showed that the loss index and intercept of the channel fading curve would change when the wearing position of antenna was changed.The human body penetration loss is independent of the channel frequency and the distance between the receiving and transmitting antennas.The established large-scale fading model is an off body(OFF-B)channel model that is highly correlated with different parts of the human body and has a body surface shadow effect and a penetration loss correction factor.The channel fading data for line-of-sight(LOS)or non-line-of-sight(NLOS)links is measured in an OFF-B or non-body(NO-B)environment.The model details the channel characteristics of different parts of the human body.Compared with general models,it can accurately describe the propagation environment of in vitro channels.(2)The channel characteristics of wearing antennas in different parts of the human body were studied.Firstly,the in vitro channels in LOS and NLOS communication environments were measured,and the power delay spectrum,root mean square(RMS)delay spread,and other parameters of the channel were calculated.The channel fading conditions in different parts of the human body were compared and analyzed,The results show that the RMS delay spread of the small-scale fading curve has a certain correlation with the wearable position and the transceiver distance.Finally,a small-scale modified model based on Saleh Valenzuela was established.This model considered the impact on the channel caused by changes in the height difference between the receiving and transmitting antennas caused by different parts of the human body,and corrected the received signal phase,the power fading index of rays between and within the multi-path cluster.Finally,verification proved that this model can more accurately describe the indoor body area network wireless channel propagation environment.