Effect of Limiter Based PAPR Reduction for Massive MIMO Systems

In massive multi-input multi-output (mMIMO) orthogonal frequency division multiplexing (OFDM) systems, reduction of high peak-to-average power ratio (PAPR) is a challenging problem. Although deliberate amplitude peak limiting is a promising PAPR reduction approach, it causes un-desired nonlinear in-band distortion and out-of-band radiation. Thus, the joint use of a peak limiter and band-limitation filter such as clipping-and-filtering (C&F) is required. The objective of this paper is to evaluate the effect of C&F based PAPR reduction for mMIMO-OFDM systems, where a band-limitation filter is designed to limit out-of-band radiation due to clipping while mitigating peak amplitude regrowth due to filtering. We discuss the effect of utilizing extra degrees of freedom for compensating in-band distortion due to C&F in mMIMO systems. Simulation results verified the effectiveness of the above approach in terms of instantaneous peak power, adjacent channel leakage power ratio (ACLR) and signal-to-distortion power ratio (SDR) in mMIMO-OFDM downlink.