The coal mine internet of things (IoT) communication system is used for real-time monitoring of mining production to ensure the safety and reliability of personnel and equipment in the mine. To eliminate multipath fading in the process of wireless communication in mines. multiple-output multiplexing (MIMO) and orthogonal frequency division multiplexing (OFDM) technologies are introduc... https://yeswellneses.shop/product-category/herbal-tea/