called Massive MIMO (multiple-input multiple-output), is a key technology for increasing the
capacity of 5G networks and beyond. While originally conceived for conventional sub-6 GHz
frequencies, Massive MIMO (mMIMO) is also ideal for frequency bands in the range 30-300
GHz, known as millimeter wave (mmWave). Despite conceptual similarities, the way in which
mMIMO can be exploited in these bands is radically different, due to their specific …