Peak-to-average power ratio and power efficiency considerations in MIMO-OFDM systems

Peak-to-average power ratio (PAR) reduction is a powerful tool that can increase power efficiency and reduce distortion noise in MIMO-OFDM systems. Various PAR metrics have been used in the MIMO-OFDM literature without justifications regarding the physical mechanisms that support those PAR definitions. In this paper, we show that in order to deliver high power efficiency, two MIMO-OFDM linear-scaling schemes are possible: one that scales all MIMO branches with the same factor and another that uses a different scaling factor for each branch. For each system, we derive a meaningful PAR metric that should be used.