Research On Wireless Body Area Network Channel Model

Wireless body area network (WBAN) is an emerging technology that combinesminiaturized sensors impanted in watches,mobile phones and other portable devices, as wellas implanted devices inside the human body into wireless communication systems. Featuringsmall network scale and low power, WBAN differs from conventional network in manyaspects. Plenty of technical problems remain to be solved since WBAN is still at its earlystage.Due to issues like human tissue, occlusion of the human body, body motion, and theexternal environment factors, the electromagnetic environment for WBAN is rather complexand its signal transmission channel is difficult to model. Research on signal transmissionchannels concentrates on3types: inside body, surround the body and outside the body. Thispaper studies the WBAN channel models, including statistical channel model and a surfacederived from Maxwell’s equations. The main work can be summarized as follows:1) Starting from the Maxwell’s equations we derive the electromagnetic wavepropagation characteristic equation for the cases around the body and inside body. Linearantenna channel model based on the existing monopole model is derived and it’s proved thelinear antenna channel model can be simplified to the monopole model.2) Considering it’s difficult to solve Maxwell’s equations for WBAN in the channelmodelling because of complex boundary conditions, we studies two WBAN statisticalchannel models, i.e. path loss model and power delay distribution model(PDP). The formerone can be used for a variety of bands, the latter one is generally used for ultra-wideband(UWB) band WBAN channel modeling.Finally, this paper also accomplishes the three WBAN models with Matlab simulationand analysis. We draw a conclusion about the relationship between path loss in WBANchannel with distance and frequency. So specifically when frequencies are less than10MHz,antenna coupling models would be better for WBAN channel models.