Multiple input and multiple output (MIMO) technology is able to offer a large increase in the capacity of 5G systems, without requiring a considerable increase in bandwidth or power required for transmission. This paper starts by presenting an overview of the concepts from MIMO systems. Combined with millimetre waves, massive MIMO systems, where the number of antennas in the base station and the number of users are large, is a promising solution for 5G. In this paper, Software Defined Radio (SDR) implementations have been performed considering a platform with Matlab code applied to MIMO 2x2 implemented with Universal Software Peripheral Radios (USRPs). MIMO is the starting point for future hardware building blocks involving massive MIMO systems. As a future research, a more complex system will be implemented, and the use of a MIMO multi-antenna system with USRP hardware will be explored.