Energy efficient time-modulated OFDM directional modulation transmitters

In this study, a reconfigurable power divider (RPD) enabled energy efficient direction modulation (DM) transmitter for orthogonal frequency division multiplexing (OFDM) modulated data transmission is proposed. The RPD can smartly select the output ports and operate as a power divider or a switch with appropriate control conditions. Hence, the RPD is able to recycle the energy in the 'OFF' state antennas, which is otherwise wasted in the conventional DM transmitter constructed using a fixed power divider and switches. It has been shown in a 4-element array example that the newly proposed RPD-based OFDM DM transmitter can provide 1.5-7.8 dB SNR gains (or in the other way, reducing power consumption by 1.5-7.8 dB) for different excitation strategies.