Adaptive Interference Rejection in Human Body Communication using Variable Duty Cycle Integrating DDR Receiver
Shovan Maitya, Debayan Dasb and Shreyas Senc
School of Electrical and Computer Engineering, Purdue University.
amaity@purdue.edu
bdas60@purdue.edu
cshreyas@purdue.edu
ABSTRACT
Connected smart wearable devices are becoming increasingly popular with the advent of cheap, miniaturized, ultralow- power computing and communication. Human Body Communication (HBC) is emerging as an alternative to Wireless Body Area Network (WBAN) for communication among these devices, as it provides higher energy-efficiency and security. One of the biggest bottleneck of HBC is the interference picked up due to the human body antenna effect, with Signal to Interference Ratio often worse than -20dB. An interference robust integrating dual data rate (DDR) receiver is introduced which can adapt itself to changing interference conditions and provide high interference rejection by Pulse Width Modulation of integration clock, thus dynamically changing its duty cycle. The theory, architecture of the receiver is developed along with the adaptation algorithm to train the receiver to find the optimum duty cycle of operation. System-level simulations show > 20 dB of rejection even in presence of variable interference frequencies.
Keywords: Human Body Communication (HBC), Integrating receiver, DDR, Body Coupled Communication (BCC), Pulse Width Modulation (PWM), Interference tolerance, Adaptive filter.
