MIMO, or Multiple-Input Multiple-Output, is a wireless technique developed to meet the growing demand for bandwidth in the wireless communication field. In recent years, MIMO radar has become popular in radar research for its ability to reduce target radar cross-section fading and enhance spatial diversity gain. By combining antennas at the transmitter and receiver, MIMO enables excellent spectral and energy efficiency with relatively simple processing, making it a key technology for the next generation of networks. A recent proposal introduced an optimal MIMO radar detector, which includes optimal transmit and receive weightage, for detecting stationary targets. This paper highlights the role of MIMO radar in promoting efficient target detection and its significance in 5G green communication. It also delves into the fundamental principles of MIMO radar technology. MIMO antennas are seen as promising elements for the development of 5G systems. To fully realize the potential of intelligent sensing systems, a deeper understanding of the MIMO system and its associated challenges is crucial for the successful deployment of 5G and future networks.