A method for wirelessly transmitting data using a plurality of transmission layers includes estimating a number of data vector symbols to be allocated to one or more user data codewords during the subframe and determining a number of bits in the one or more user data codewords. The optical filter 11 do not deviate from the optical path, and infallibly eliminate light in the infrared region which becomes heat radiation. When the protrusion is pressed, the movable contact is elastically reversed, and the first fixed contact and the second fixed contact become electrically conductive with each other via the movable contact.