Digital signal

Digital signal The digital signal is a signal processed in a certain way and converted into digits. Usually these digital signals are related to actual analog signals. To simplify this let's take the principle of information transfer using Morse code as an example of a digital signal. Previously, when information transmission via the radio signal was still developing, technical features of receiving and transmitting equipment did not allow to transmit the voice signal over long distances. So, text information was used instead of voice information. Since the text consists of letters, these letters were transmitted by means of long and short pulses of the electrical tone signal. In such signal transmission bits of information are conventionally called the "dot" and the "dash". A short tone signal stood for a dot, and a long tone signal - for a dash. Each letter of the alphabet consisted of a specific set of dots and dashes. For example, the letter A was denoted by the dot-dash combination, and the letter B - dash-dot-dot-dot. The digital signal is based on a very similar principle of information coding, but for other bits of information. Any digital signal consists of the so-called "binary code". Here a logical zero and a logical one are used as bits of information. If, for example, we take an ordinary flashlight and switch it on it will signify a logical one, if we switch it off, it will signify a logical zero. In digital electronic chips a certain level of voltage in volts is are taken as one and zero. For example, a logical one will mean 4.5 volts, and a logical zero - 0.5 volts. Naturally, for each type of digital chips, load values of the logical zero and one are different. Any letter of the alphabet, as in the Morse code example above, in digital form will consist of a number of zeros and ones put in a specific sequence, which in turn are part of logic pulses packets. Almost any kind of transmitted electrical signal (including the analog signal) can be encoded in a digital code, and it does not matter whether it will be a picture, a video signal, an audio signal, or text information. And we can pass these kinds of signals, virtually simultaneously (in a single digital stream). In its electrical features the digital signal has a larger information transmission capacity than the analog signal. Likewise, digital signals can be transmitted at a greater distance than analog signals but without reducing the quality of the transmitted signal.

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