For over years we use different things to convey a signal but in this course we learn how to convey a signal by using modern techniques.
Let’s start from information source it is basically a sensor used to convert any physical quantity into measurable quantity e.g if input signal is light then sensor will convert it into electric signal. The next step is Transmitter modifies the baseband signal for efficient transmission. The Channel is a medium such as wire,coaxial cable,an optical fiber through which transmitter output is sent. The Receiver reprocesses the signal received from the channel without making any change at transmitter and channel. Output Transducer once again convert the signal into it’s original form. Destination is the place where you transmit the signal.
Above we discussed about channel but it is more known for distortion. There are 2 types of distortions linear and non-linear distortion. The SIGNAL-TO-NOISE RATIO is defined as the ratio of signal power to noise power. We know that when noise level increases signal strength decreases with increase in distance from transmitter.
The maximum data that we can transmit between two ranges of frequencies e.g if a signal rages from 250 Hz to 500 Hz then it’s bandwidth is 250 Hz. If we compressed the time with factor 2 then it’s data rate transmission speed is doubled. To send the signal without distortion then its bandwidth is also doubled.
The Signal power plays an important role in signal transmission. Signal quality also depends upon power. If a signal have more power then its absolute that it have more amplitude. The larger SNR allows transmission over a longer range.