In-vivo MIMO Channel Characteristics Analysis and Modeling Based on Skin-fat Model at Terahertz Frequency
To investigate transmission characteristics of in-vivo Mmultiple Input Multiple Output (MIMO)communication systems at TeraHertz (THz) frequency, a precise skin-fat model is constructed at 0.8~1.2 THz. Full wave electromagnetic simulations are conducted on the vertical and horizontal links in the skin-fat model, the characteristics of terahertz in-vivo channel are analyzed, and a terahertz in-vivo path loss model is established. Firstly, the skin-fat model is constructed based on the dielectric properties of human tissue at terahertz frequency and the anatomical structure of human skin. Secondly, the path loss and shadow fading of the three links are compared and analyzed, and a terahertz in-vivo path loss model with equivalent absorption factor is proposed. Finally, the Rice K factor, the root mean square delay extension, and the MIMO capacity of the three links are analyzed. The results demonstrate that the terahertz in-vivo path loss model with equivalent absorption factor can more accurately describe the path loss of extended distance in vertical link 2, on-body transmitter can provide enhancement in MIMO capacity. This work can give an insight into the design and optimization of THz in-vivo communication systems.