Frequency division multiplexing is when a communication medium divides its frequency in order to carry a number of different signals at once. Broadband DSL uses this to transport large amounts of data quickly.
Frequency-division multiplexing, wavelength-division multiplexing, and time-division multiplexing.
Frequency-division multiplexing and wavelength-division multiplexing
Do you mean FDM or Frequency Division Multiplexing? If so, FDM is the division of a high frequency carrier into separate non-overlaping bands to be modulated by separate inputs. It's the modulation of several low frequency channels onto a high frequency carrier. Voice channels are low bandwidth inputs relative to the broadband carrier used to broadcast them.
what is function of amplitude division multiplexing
In Baseband, data is sent as digital signals through the media as a single channel that uses the entire bandwidth of the media. Baseband communication is bi-directional, which means that the same channel can be used to send and receive signals. In Baseband no frequency-division multiplexing is not possible. (Multiplexing (short muxing) is a process where multiple analog message signals or digital data streams are combined into one signal over a shared medium.)Broadband sends information in the form of an analog signal. Each transmission is assigned to a portion of the bandwidth, hence multiple transmissions are possible at the same time. Broadband communication is unidirectional, so in order to send and receive, two pathways are needed. This can be accomplished either by assigning a frequency for sending and assigning a frequency for receiving along the same cable or by using two cables, one for sending and one for receiving. In broadband frequency-division multiplexing is possible
The basic difference between fdm and fdma is that fdm is used in wired system where as fdma is used in wireless communication.
multiplexing refeers to the transmission of different signals in the same channel simultaneously. There are many forms of multiplexing that can be used, including frequency division multiplexing(FDM) where individual signals are transmitted over adjacent , non overlapping frequency bands. they are transmitted in parallel and simultaneously in time. In time division multiplexing(TDM) each signal is allowd to use the whole bandwidth for a certain period of time. Multiplexing is needed so that the available channel can be used efficiently and also to save costs. There is too much to know about multiplexing, here is just a short overview. One thing that one has to know is multiple access.
Currently the mobiles use GSM(Geo Synchronous Mobiles ) and CDMA(Code Division Multiple Accesss) techniques. GSM inturn uses TDMA(Time Division Multiplexing) or FDMA(Frequency Division Multiplexing) or sometimes both to fit in the required criteria.
FDM stnds for frequency division multiplexing and it is used only in case of analog signals because analog signals are continuous in nature and the signal have frequency. TDM-stands for time division multiplexing and it is used only in case of digital signals because digital signals are discrete in nature and are in the form of 0 and 1s. and are time dependent.
WDM (wavelength division multiplexing)
OFDM means Orthogonal frequency-division multiplexing. This is a method on encoding data which in digital television and radio. It is also used on 4G networks.
Orthogonal frequency-division multiplexing (OFDM) is a method of encoding digital. Pilot signals and training symbols (preambles) may also be used for time.