Every day people are faced with the use of electronic devices. Without them, modern life is impossible. After all, we are talking about a TV, radio, computer, telephone, multicooker and more. Previously, a few years ago, no one thought about what signal is used in each operable device. Now the words "analog", "digital", "discrete" have long been heard. Some of the signals listed above are of high quality and reliable.
Digital transmission came into use much later than 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 advanced.
Every person faces the concept of "discreteness" all the time. If you translate this word from Latin, then it will mean "discontinuity". Going deep into science, we can say that a discrete signal is a method of transmitting information, which implies a change in time of the carrier medium. The latter takes any value from all possible. Now discreteness is fading into the background, after the decision was made to produce systems on a chip. They are integral, and all components closely interact with each other.friend. In discreteness, everything is exactly the opposite - each detail is completed and connected to others through special communication lines.
Signal
A signal is a special code that is transmitted into space by one or more systems. This wording is generic.
In the field of information and communication, a signal is a special carrier of any data that is used to transmit messages. It can be created but not accepted, the last condition is optional. If the signal is a message, then "catching" it is considered necessary.
The described data transfer code is given by a mathematical function. It characterizes all possible changes of parameters. In radio engineering theory, this model is considered basic. In it, noise was called the analogue of the signal. It is a function of time that freely interacts with the transmitted code and distorts it.
The article describes the types of signals: discrete, analog and digital. The main theory on the topic being described is also briefly given.
Types of signals
There are several types of signal classification available. Consider what types are.
- According to the physical medium of the data carrier, an electrical signal, optical, acoustic and electromagnetic are separated. There are several other species, but they are little known.
- According to the method of setting, the signals are divided into regular and irregular. The former are deterministic data transfer methods that are specified by an analytic function. Random ones are formulated due to the theory of probability, and they also take on any values at different time intervals.
- Depending on the functions that describe all signal parameters, data transmission methods can be analog, discrete, digital (a method that is level quantized). They are used to power many electrical appliances.
Now the reader knows all kinds of signaling. It will not be difficult for anyone to understand them, the main thing is to think a little and remember the school physics course.
What is the signal processed for?
The signal is processed in order to transmit and receive the information that is encrypted in it. Once it is extracted, it can be used in a variety of ways. In some situations, it will be reformatted.
There is another reason for processing all signals. It consists in a slight 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, filtering, convolution, correlation. They are needed 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 often needed to generate signals. Most often, both of them are used only in a situation with the use of DSP technologies. In other cases, only the use of a DAC will do.
When creatingphysical analog codes with the further use of digital methods rely on the received information, which is transmitted from special devices.
Dynamic Range
The range of the signal is calculated by the difference between the higher and lower volume levels, which are expressed in decibels. It completely depends on the work and the features of the performance. We are talking about both music tracks and ordinary dialogues between people. If we take, for example, an announcer who reads the news, then his dynamic range fluctuates around 25-30 dB. And while reading a work, it can grow up to 50 dB.
Analog signal
An analog signal is a time-continuous way of transmitting data. Its disadvantage 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 important data is in the code, and where the usual distortions.
This is exactly why digital signal processing has become very popular and is gradually replacing analog.
Digital signal
Digital signal is a special data stream, it is described by discrete functions. Its amplitude can take on a certain value from those already given. While the analog signal is capable of receiving a huge amount of noise, the digital one filters out most of the received noise.
Besides this, this type of data transmission transfers information without unnecessary semanticloads. Several codes can be sent through one physical channel at once.
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. Nowadays, such a signal is considered the most popular. This is due to ease of use.
Application of digital signal
What is the difference between a digital electrical signal and others? The fact that he is able to perform a complete regeneration in the repeater. When a signal with the slightest interference enters the communication equipment, it immediately changes its form to digital. This allows, for example, a TV tower to form a signal again, but without the noise effect.
In the event that the code arrives already with large distortions, then, unfortunately, it cannot be restored. If we take analog communication in comparison, then in a similar situation, the repeater can extract part of the data, spending a lot of energy.
When discussing cellular communications of different formats, with strong distortion on a digital line, it is almost impossible to talk, since words or whole phrases are not heard. Analog communication is more effective in this case, because you can continue to carry on a dialogue.
It is precisely because of such problems that repeaters form a digital signal very often in order to reduce the gap in the communication line.
Discrete signal
Now every person uses a mobile phone or some kind of “dialer” on hiscomputer. One of the tasks of devices or software is the transmission of a signal, in this case a voice stream. To carry a continuous wave, a channel is needed that would have a higher level bandwidth. That is why the decision was made to use a discrete signal. It does not create the wave itself, but its digital form. Why? Because the transmission comes from technology (for example, a phone or a computer). What are the advantages of this type of information transfer? It reduces the total amount of data transferred and makes batching easier.
The concept of "discretization" has long been consistently used in computer technology. Thanks to such a signal, not continuous information is transmitted, which is completely encoded with special symbols and letters, but data collected in special blocks. They are separate and complete particles. This encoding method has long been relegated to the background, but has not completely disappeared. With it, you can easily transfer small pieces of information.
Comparison of digital and analog signals
When buying equipment, hardly anyone thinks about what types of signals are used in this or that device, and even more so about their environment and nature. 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. Instead comes digital communication. You need to understand what is at stake and what humanity refuses.
In short,analog signal is a way of transmitting information, which implies the description of data by continuous functions of time. In fact, speaking specifically, the amplitude of 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.
Passing 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 “smooths” them. Due to new technologies, this method of data transmission is capable of restoring all the original information on its own without the intervention of a scientist.
Speaking of television, we can already say with confidence: analog transmission has long outlived its usefulness. Most consumers are moving to a digital signal. The disadvantage of the latter is that if any device is capable of receiving an analog transmission, then a more modern method is only a special technique. Although the demand for the outdated method has long fallen, yet these types of signals are still not able to completely disappear from everyday life.
