Analysis of dense array massive MIMO with practical constraints

Practical constraints on hardware limit the benefit of super-directive dense antenna arrays for massive MIMO. We analyze the signal-to-noise ratio (SNR) at the receiver and its dependence on the matching network strategy with a constraint on the total power supplied by power amplifiers (PA) as opposed to that of the radiated power. We consider several beamforming strategies and derive optimal PA current based on (a) phase-only versus phase and magnitude beamforming and (b) frequency-flat versus frequency-selective beamforming. Through simulations, we study the impact of variation in number of antennas/ interantenna spacing, frequency, angle, matching network strategy, and beamforming strategy on the received SNR.