PAPR Reduction Using Average Transmit Signal Power Difference Among Transmit Antennas for Massive MIMO-OFDM with Uniform Planar Array

This paper investigates a peak-to-average power ratio (PAPR) reduction method for the massive multiple-input multiple-output (MIMO)-orthogonal frequency division multiplexing (OFDM) with uniform planar array (UPA) antennas. To accommodate the large variation in average transmit signal power among antennas in UPA scenario, we propose a new PAPR reduction method using average transmit signal power and the null space in the MIMO channel. First, the proposed method sufficiently reduces the PAPR at the antennas with large average transmit signal power by adding the peak cancellation (PC) signal without null space projection. After that, a compensating signal that cancels the interference caused by the PC signal at the receiver is added to the transmission signal of antennas with small average signal power. Finally, the proposed method removes the residual peak signals for all transmit antennas by the peak cancellation with channel-null constraint (PCCNC) method, which we previously reported. The proposed method allows the system to use all the transmit antennas for data transmission while suppressing the PAPR aggressively. Simulation results show that when employing a nonlinear power amplifier with UPA, the proposed method increases throughput compared to the conventional PCCNC and the method that does not use the null space in the MIMO channel.