Least-squares iterative PAR reduction for point-to-point large-scale MIMO-OFDM systems

This paper addresses peak-to-average ratio (PAR) reduction in orthogonal frequency division multiplexing (OFDM) based large-scale multiple-input multiple-output (MIMO) systems. We propose a new technique for PAR reduction in point-to-point scenarios. The last eigenchannels of a massive MIMO channel are often very weak. Not using them for data transmission will offer redundancy for PAR reduction. These eigenchannels are used to approximate the peaks which exceed a given target value in a least squares fashion. This approximate exceedence model is then subtracted from the original signal in time domain for PAR reduction. It has been shown through simulation results that a considerable gain can be obtained with the proposed method with marginal increase in the average power and almost negligible loss in the channel capacity.