There is no definitive answer to this question as the term "massive MIMO" can mean different things to different people. Generally speaking, massive MIMO refers to a system that uses a large number of antenna elements to achieve high performance. This can be done in a number of ways, such as using a large number of small antenna elements, or a smaller number of large antenna elements. There are a number of benefits that can be achieved with massive MIMO, such as improved spectral efficiency, increased capacity, and better energy efficiency.
