However, the IEEE 802.15.7 standard is out-of-date, it fails to consider the latest technological developments in the field of optical wireless communications, specifically with the introduction of optical orthogonal frequency-division multiplexing ( O-OFDM ) modulation methods which have been optimized for data rates, multiple-access and energy efficiency.
42.
In most textbooks, the term analog transmission only refers to the transmission of an analog message signal ( without digitization ) by means of an analog signal, either as a non-modulated baseband signal, or as a passband signal using an analog modulation method such as ASK . Note that these methods are covered in textbooks named digital transmission or data transmission, for example.
