On the performance of Massive MIMO cellular systems with power amplifiers

Orthogonal Frequency-Division Multiple Access (OFDMA) is the modulation of choice due to its robustness to time-dispersive radio channels, low-complexity receivers, and simple combining of signals from multiple transmitters in broadcast networks. However, the transmitter design for OFDMA is more costly, as the Peak-to-Average Power Ratio (PAPR) of an OFDMA signal is relatively high, resulting in the need for highly linear RF power amplifiers (PA). This problem becomes more compounded when a large number of PAs is required, as in Massive MIMO. In this paper, we discuss the impact of PAs on cellular systems. We show the constraints that PAs introduce, and we take these constraints into consideration while searching for the optimum set of transmitter and receiver filters. Moreover, we highlight how Massive multiple-input and multiple-output (MIMO) cellular networks can relax PAs constraints resulting in low cost PAs, while maintaining high performance. The performance is evaluated by showing the probability of error curves and signal-to-noise-ratio curves for different transmit powers and different number of transmit antennas.