Power Optimized PA Clipping for MIMO-OFDM Systems

For a multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) system that is being pushed into power amplifier (PA) saturation, this letter investigates power-optimized PA clipping. Our goal is to identify the optimum clipping level for a MIMO-OFDM system that delivers the desired bit error rate (BER) with minimum power consumption in the PA. We present a complete theoretical framework resulting in an analytical expression for the BER of a MIMO-OFDM system subject to PA clipping. PA power saving is addressed by the total degradation metric, which shows that as much as 6dB power reduction can be achieved by proper choice of the clipping level.