Joint Waveform and Beamforming Optimization for MIMO Wireless Power Transfer

In this paper, we study a multi-sine multiple-input multiple-output (MIMO) wireless power transfer (WPT) system with the objective to increase output DC power. We jointly optimize waveform and beamforming accounting for rectenna nonlinearity, consider two combining schemes rectennas at receiver, namely RF combinings. For combining, transmit are optimized, as function of channel state information (CSI). optimal receive beamformings provided in closed form is optimized. also practical circuit using phase shifter combiner waveform, beamforming, analog adaptive CSI. Two types performance evaluations, based on nonlinear model accurate realistic simulations, provided. The evaluations demonstrate that joint design can by leveraging gain, frequency diversity nonlinearity. It shows provides higher than beamforming-only relative gain 180% two-transmit antenna sixteen-sinewave two-receive setup.