On the SINR in Massive MIMO Networks with MMSE Receivers

Massive multiple-input-multiple-output (MIMO) wireless communications refers to the idea equipping transmitters with a very large number of antennas and has been shown to potentially allow for orders of magnitude improvement in spectral and energy efficiency using relatively simple (linear) processing. In this letter, we consider a scenario that multiple links transmit in the vicinity of each other simultaneously using the same time-frequency resource. With the limitations of an infinite number of antennas for the receiver at each link, we use minimum-mean-squared-error (MMSE) receivers to suppress the interference. The asymptotic signal to interference and noise ratio (SINR) at each link´s receiver is analyzed by using matrix theory. In addition, we find substitute beamforming methods to achieve the same performance compared to the MMSE receiver when massive MIMO is used. Finally, the upper and lower bounds on the SINR in the limit of nonideal channel conditions are derived.