- Digital Communication is a mode of communication where the information or the thought is encoded digitally as discrete signals and electronically transferred to the recipients.
- Digital Communication is one of the most commonly used modes of communication now a days.
Basic Elements of Digital Communication System:
- Information Source and Input Transducer: The source of information can be analog or digital, e.g. analog such as audio or video signal, digital such as teletype signal.
- Source Encoder: The signal produced by source is converted into digital signal consists of 1's and 0's.The process of efficiently converting the output of analog or digital source into a sequence of binary digits is known as source encoding.
- Channel Encoder: The purpose of the channel encoder is to introduced, in controlled manner, some redundancy in the binary information sequence that can be used at the receiver to overcome the effects of noise and interference encountered in the transmission on the signal through the channel.
- Digital Modulator: The binary sequence is passed to digital modulator which in turns convert the sequence into electrical signals so that we can transmit them on channel.
- Channel: The communication channel is the physical medium that is used for transmitting signals from transmitter to receiver.
- Digital Demodulator: The digital demodulator processes the channel corrupted transmitted waveform and reduces the waveform to the sequence of numbers that represents estimates of the transmitted data symbols.
- Channel Decoder: This sequence of numbers then passed through the channel decoder which attempts to reconstruct the original information sequence from the knowledge of the code used by the channel encoder and the redundancy contained in the received data.
- Source Decoder: Source decoder tries to decode the sequence from the knowledge of encoding algorithm. And which results in the approximate replica of the input at the transmitter end.
- Output Transducer: Finally we get the desired signal format analog or digital.
Applications:
- Speech Processing
- Speech Recognition
- Digital Image Processing
- Audio Signal Processing
