In this note, we are going to know about the Basic Block Diagram of Digital Communication System. Welcome to Poly Notes Hub, a leading destination for engineering notes for diploma and degree engineering students.
Author Name: Arun Paul.
Basic Block Diagram of Digital Communication System
Here is the block diagram of digital communication system with explanation –
- Information Source: The information source is the origin of the message that has to be sent. It could be human voice, a text file, a video feed, or another type of data. This data, which may originally be in analog or digital form, serves as the raw input to the communication system. The system’s ultimate purpose is to accurately and efficiently send this information to the receiver while preserving the original message’s content and intent.
- Source Encoder: The source encoder converts the original message to an appropriate digital format, usually a binary sequence of 0s and 1s. It also compresses the data to remove redundant information and save the use of bandwidth. For example, a JPEG compressor for photos or MP3 for sounds. The goal is to make the message compact and transmittable without sacrificing vital information. It ensures efficient use of communication resources and speeds up data transfer.
- Channel Encoder: This block adds redundancy to the data using error detection and correction codes such as Hamming, Reed-Solomon, or CRC. The goal is to safeguard the data from noise and errors that may arise during transmission via the channel. These extra bits assist the receiver in identifying and correcting faults, so assuring data integrity. Even if the channel is noisy or unreliable, the channel encoder improves the probability of receiving the original data without distortion or corruption.
- Modulator: The modulator turns encoded binary data into an analog signal that may be sent across physical mediums such as coaxial cables, air, or optical fiber. It employs digital modulation techniques like Amplitude Shift Keying (ASK), Frequency Shift Keying (FSK), and Phase Shift Keying (PSK). This procedure converts the bits into waves that can pass through the medium efficiently. Modulation is essential for matching the parameters of the communication channel and minimizing the influence of interference.
- Transmission Channel: The transmission channel is the medium by which the modulated signal travels from the transmitter to the receiver. It can be either wired, like fiber optics, or wireless, like radio waves. The signal may meet problems like as noise, interference, or attenuation, lowering its quality. The channel is regarded as the most unpredictable component of the system, and appropriate encoding/modulation techniques are employed to mitigate the consequences of these disruptions during transmission.
- Demodulator: The demodulator on the receiving end performs the inverse modulation process. It extracts the digital signal (binary data) from the received analog waveform. This step is crucial because the signal may have been distorted or degraded as it traveled through the transmission line. The demodulator must recover the correct sequence of bits as precisely as possible so that the receiver can decode and interpret the transmitted message.
- Channel Decoder: The channel decoder receives the potentially error-ridden bitstream and corrects the mistakes with the redundancy introduced by the channel encoder. It employs decoding techniques to obtain the most precise representation of the original binary data. This ensures that even if bits are flipped or lost during transmission, the data’s integrity is maintained. This process is critical for ensuring the stability of digital communication systems, particularly across noisy or long-distance networks.
- Source Decoder: The source decoder reverses the procedure carried out by the source encoder. It decompresses binary data and converts it back to a human-readable format such as text, audio, or video. For example, it may decode an MP3 audio file or decompress an image file. The accuracy of this block is critical to maintaining the original message’s quality and content. It guarantees that the user receives a message that is clear, full, and relevant.
- Information Sink: This is the sent message’s final destination. It could be a user interface, display monitor, speaker, printer, or any other equipment that conveys the message to the end user. The information sink interprets data in a way that achieves the communication goal. It is the receiver’s point of interaction with the message, and the overall effectiveness of the communication system is determined by the precision and clarity with which the information is given here.
Advantages of Digital Communication System
Here we have listed some digital communication system advantages –
- High Noise Immunity: Digital transmissions are less susceptible to noise. Even if the signal is disrupted, error correcting techniques can retrieve the original data, making digital communication more dependable over long distances or in loud surroundings.
- Efficient Data Compression: Data compression is supported by digital systems, allowing for smaller file sizes while maintaining high quality. This reduces bandwidth use and speeds up transmission, allowing more data to be transferred over restricted channels.
- Better Signal Quality: Digital signals can be regenerated with no loss in quality. The signal remains clear even after many transmissions, as opposed to analog signals, which degrade with distance.
- Multiplexing Capability: Techniques such as Time Division Multiplexing (TDM) enable many signals to share the same channel, increasing bandwidth efficiency and lowering infrastructure costs.