Frequency Division Multiplexing
Frequency Division Multiplexing (FDM) is a technique used in telecommunications to transmit multiple signals simultaneously over a single communication medium by dividing the total bandwidth available into a series of non-overlapping frequency bands, each carrying a separate signal.
Multiplexing Technique: FDM is a form of multiplexing, which allows multiple independent signals to share the same transmission medium, such as a cable or a radio wave.
Guard Bands: To prevent interference between adjacent channels, FDM typically employs guard bands – small frequency ranges that separate channels and keep signals distinct.
Applications: Besides telephone systems and radio broadcasting, FDM is also used in television broadcasting, satellite communication, and some forms of early broadband Internet access.
Limitations and Advancements: While FDM was pivotal in early telecommunications, it has limitations in terms of bandwidth efficiency compared to newer digital multiplexing techniques like Time Division Multiplexing (TDM) and Orthogonal Frequency-Division Multiplexing (OFDM). However, the basic principles of FDM are still applied in various modern technologies.
Frequency Division Multiplexing was a foundational technology in the development of telecommunications, enabling more efficient use of communication channels and paving the way for advanced digital multiplexing techniques.