Performance evaluation of multilevel ASK communication for a multi-hop wireless resonance system

Wireless power transmission (WPT) via electromagnetic resonance has been focused on by researchers in related fields. Also, a multi-hop wireless power transmission system successfully extends power transmission distance by using multiple resonators. Sending data along with electrical power is one of the most important but missing pieces for the realization of the multi-hop WPT system. Different from radiative approach based on antennas, switching speed of waveform on the resonators is significantly slower because of resonance. Therefore it is very difficult to increase symbol rate of communication. To overcome this problem, we exploit the fact that signal-to-noise ratio (SNR) is higher in WPT because input power level is typically high. In this paper we adopt Multilevel Amplitude-Shift Keying (Mary ASK) to increase bit per symbol rather than symbol rate, aiming to improve the bit rate. We evaluate the communication performance of a multi-hop WPT system and focus on M-ary ASK for high communication speed. We conduct the experiment using M-ary ASK modulation and show the system throughput via the symbol rate and optimized bit per symbol (Log₂M) for M-ary ASK.