Types of signals: analog, digital, discrete

Every day people come across the use of electronic devices. Without them, modern life is impossible. After all, we are talking about TV, radio, computer, telephone, multivark and other. Earlier, a few years ago, no one thought about what kind of signal is used in every workable device. Now the words "analog", "digital", "discrete" have long been heard. Some of the signals listed above are of high quality and reliable.

The digital transmission was used much later than the analog transmission. This is due to the fact that such a signal is much easier to maintain, and the technology at that time was not so improved.

Everyone is constantly confronted with the notion of "discretion". If you translate this word from the Latin language, then it means "intermittence". Deepening far into science, we can say that a discrete signal is a method of transmitting information, which implies a change in the time of the carrier medium. The latter takes any value from all possible. Now the discreteness goes to the background after the decision was made to produce systems on the chip. They are integral, and all components closely interact with each other. In discreteness, however, everything is exactly the opposite - every detail is completed and connected with others due to special communication lines.

Signal

A signal is a special code that is transmitted to the space by one or more systems. This formulation is general.

In the field of information and communication, a special media of any data is used as a signal, which is used to transmit messages. It can be created, but not accepted, the latter condition is not necessary. If the signal is a message, its "catching" is considered necessary.

The data transfer code described is given by a mathematical function. It characterizes all possible changes in the parameters. In radio engineering theory, this model is considered basic. In her, the analogue of the signal was called noise. It is a function of time, which interacts freely with the transmitted code and distorts it.

The article describes the types of signals: discrete, analog and digital. Also, the basic theory on the topic described is briefly given.

Types of signals

There are several types of classification of available signals. Let's consider what kinds there are.

1. The physical medium of the data carrier is separated by an electrical signal, optical, acoustic and electromagnetic. There are several more species, but they are little known.
2. By the method of setting the signals are divided into regular and irregular. The first are deterministic methods of data transmission, which are specified by an analytic function. The random ones are formulated at the expense of the probability theory, and also they take any values at different time intervals.
3. Depending on the functions that describe all the signal parameters, the methods of data transmission can be analog, discrete, digital (a method that is quantized in terms of level). They are used to provide operation of many electrical appliances.

Now the reader knows all kinds of signaling. To understand them is not difficult for any person, the main thing is to think a little and remember the school course of physics.

Why is the signal processed?

The signal is processed to transmit and receive information that is encrypted in it. Once it is extracted, it can be used in various ways. In some situations, it will be reformatted.

There is another reason for processing all signals. It consists in a small compression of frequencies (so as not to damage the information). After that, it is formatted and transmitted at slow speeds.

Special methods are used in analog and digital signals. In particular, filtration, convolution, correlation. They are necessary to restore the signal if it is damaged or has noise.

Creation and formation

Often, analog-to-digital (ADC) and digital-to-analog (DAC) converters are needed to generate signals . Most often they are both used only in the situation with the use of DSP-technologies. In other cases, only the use of a DAC is suitable.

When creating physical analog codes with the further application of digital methods rely on the information received, which is transmitted from special devices.

Dynamic Range

The signal range is calculated by the difference between the higher and lower volume levels, which are expressed in decibels. It depends entirely on the work and features of the performance. It is both about music tracks, and about ordinary dialogues between people. If you take, for example, a speaker who reads news, then its dynamic range fluctuates around 25-30 dB. And while reading a work, it can grow up to 50 dB.

Analog signal

The analog signal is a continuous, time-based data transfer method. Its drawback is the presence of noise, which sometimes leads to a complete loss of information. Very often there are such situations that it is impossible to determine where the code is important data, and where the usual distortions.

It is because of this that digital signal processing has become very popular and is gradually replacing the analog one.

Digital signal

A digital signal is a special data stream, it is described by discrete functions. Its amplitude can assume a certain value from those already specified. If the analog signal is capable of receiving a huge amount of noise, then the digital filter filters out most of the interference received.

In addition, this type of data transfer carries information without unnecessary semantic load. Several codes can be sent through the same physical channel.

The types of digital signal do not exist, as it stands out as a separate and independent method of data transmission. It is a binary stream. In our time, this signal is considered the most popular. This is due to the ease of use.

Applying a digital signal

What is the difference between a digital electrical signal and the others? The fact that he is able to perform a full regeneration in the repeater. When a signal with the slightest interference enters the communication equipment, it immediately changes its form to a digital one. This allows, for example, the TV tower to generate a signal again, but without the noise effect.

In the event that the code arrives already with great distortion, then, unfortunately, it is not subject to recovery. If we compare analog communication, then in a similar situation the repeater can extract a part of the data, spending a lot of energy.

Discussing cellular communication of different formats, with strong distortion on a digital line, it is almost impossible to talk, since words or whole phrases are not audible. Analogue communication in this case is more effective, in fact it is possible to continue dialogue.

It is because of such problems that the digital signal repeater is formed very often in order to reduce the communication line break.

The discrete signal

Now every person uses a mobile phone or some kind of "caller" on his computer. One of the tasks of instruments or software is the transmission of a signal, in this case a voice stream. To transfer a continuous wave, you need a channel that would have a higher-capacity bandwidth. That is why it was decided to use a discrete signal. It does not create the wave itself, but its digital appearance. Why is that? Because the transfer comes from the technology (for example, a phone or a computer). What are the advantages of this type of information transfer? With it, the total number of transmitted data is reduced, and packet-based sending is easier to organize.

The concept of "discretization" has long been used steadily in the work of computer technology. Due to this signal, not continuous information is transmitted, which is completely encoded by special symbols and letters, and data collected in special blocks. They are separate and complete particles. This method of encoding has long ago moved to the background, but it did not completely disappear. With it, you can easily transfer small pieces of information.

Comparison of digital and analog signals

Buying equipment, hardly anyone thinks about what kinds of signals are used in one or another device, but about their environment and nature even more so. But sometimes you still have to deal with concepts.

It has long been clear that analog technologies are losing demand, because their use is irrational. In return, digital communication is coming. We need to understand what is at stake and what humanity refuses.

In short, an analog signal is a way of transmitting information, which means describing the data as a continuous function of time. In fact, speaking specifically, the amplitude of the oscillations can be equal to any value that is within certain limits.

Digital signal processing is described by discrete time functions. In other words, the oscillation amplitude of this method is equal to strictly specified values.

Turning from theory to practice, it must be said that the analog signal is characterized by interference. With digital, there are no such problems, because it successfully "smoothes" them. Due to new technologies, this method of data transmission is able to restore all the initial information without interference from the scientist.

Speaking of television, you can already say with confidence: analog transmission has long outlived itself. Most consumers switch to a digital signal. The downside of the latter is that if an analog transmission is capable of receiving any device, then a more modern method is only a special technique. Although the demand for the obsolete method has long fallen, still such types of signals are still not able to completely withdraw from everyday life.