Design and implementation of a HBC digital baseband system for two-hop extension star network

In Human Body Communication (HBC) system, low power is still one of the most important research issues for monitoring nodes supplied by battery. Utilizing two-hop extension star network topology is an efficient measure to reduce the average transmission power consumption and improve the stability. This paper proposes a digital baseband system for low duty cycle and low load network. When the nodes are far apart from hub relatively, the system can change the working mode to selecting relay mode automatically according to the network environment. The whole baseband system is verified on FPGA prototype platform with 2Mb/s data rate for ECG(electrocardiogram) monitoring. Under SMIC 0.13um CMOS process, the area and power are 133370 um2 and 1.619mW for node digital baseband, and 79246 um2 and 0.674mW for hub digital baseband.