Difference Between FDM and TDM

Hello, friends, I hope you all are doing great. In today’s tutorial, we will discuss the Difference Between FDM and TDM. There are 2 commonly used techniques for multiplexing the first one is TDM and the second one is TDM. The basic difference between them is that in FDM numerous signals are transferred with different frequency slots. While in TDM signals are transferred through different time slots.

Multiplexing is a technique through which numerous signal is transmitted in a common channel. In today’s post, we will look at both FDM and TDM  to compare them and find their differences. So let’s get started with the Difference Between FDM and TDM.

Difference Between FDM and TDM

FDM

• It is the method through which the net bandwidth of a single is parted in different frequency levels and every band has its on signal.
• It helps to convert a single medium used for transmission to make different mediums.
• It sends data in parallel combination

• The practical examples of this method is radio signal transmission and tv transmission.
• There is Cable TV is also an example through which numerous channels are operated.
•  It uses analog multiplexing techniques.
• It does not need any synchronization.
•  Its circuit arrangement is complicated.
•  There is crosstalk is existing.
• In a telephone system, it is used to transmit calls over multiple users.
• There is a similar technique to called wavelength division multiplexing that uses optic fiber for communication
•  The full form of FDM is Frequency Division Multiplexing.
•  Its propagating delay is sensitive.
• Its efficiency is less.
• Its price is high.

TDM

• The method that allows the transmission of numerous signals of data through the common line in different time slots is called TDM.
• Its full form is Time Division Multiplexing.
• It is a digital technique that operates on the time in place of frequency to distinguish data from another form of data.
• It is used to transmit 2 or more two signals through a single source.
• It is employed when the bit ratio of the signal source is larger than the signal sent.
• It was the first time used in the nineteenth century for telegraphy.

• It required synchronization.
• Its circuit is less complicated than the FDM.
• In this signal transmission, there is no need for crosstalk.
• Its efficiency is larger than the FDM.
•  Its price is less than FDM.
• It is normally used for digital signals but also works for the analog signal
• In this module, the time domain is parted in different time slots having a certain value.
• In this signal transmission, a digital multiplexing technique is used.
• It has two types

Synchronous TDM

Asynchronous TDM

Synchronous TDM vs Asynchronous TDM

Synchronous TDM

• Irrespective of device data use this module has the same slots for each device.
• It has the same frame slots per frame equal to input lines if it has n input lines then have n slots in a single frame.
• It does not have use of full capacity.
• The speed of input lines not higher than the capacity of the path
• It has less device connection.
• fixed and pre-defined time slots it has

Asynchronous TDM

• Multiplexers do not allocate the same time slots for each device without affecting data or the device connected.
• It provides full capacity link
• It uses a larger number of device
• It does not have pre-defined time

 FDM vs TDM

TDM

• TDM is time-division multiplexing
• It operated with digital signals also analog signals
• It has a low conflict
• It is high efficiency
• It also has time-sharing
• It needed a synchronization pulse.

FDM

• It works only for analog signals
• It comes with high conflict
• It has complex circuit wiring
• It is low efficient
• It needed a guard band.

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