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, phone, slow cooker 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 types of signals listed are high-quality and reliable.
Digital transmission began to be used much later than analog. This is due to the fact that such a signal is much easier to maintain, and the equipment at that time was not so improved.
The concept of "discreteness" is faced by every person constantly. If you translate this word from the Latin language, 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 out of all possible. Now discreteness is fading into the background, after it was decided to produce systems on a chip. They are holistic, and all components interact closely with each other. In discreteness, 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 into space by one or more systems. This wording is general.
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 not necessary. If the signal is a message, then its "catching" is considered necessary.
The described data transfer code is set by a mathematical function. It characterizes all possible changes in parameters. In radio engineering theory, this model is considered basic. In it, noise was called an analog 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. Also briefly given is the basic theory on the subject.
Types of signals
There are several types of classification of available signals. Consider what types are.
- According to the physical medium of the data carrier, an electrical signal is separated, optical, acoustic and electromagnetic. There are several more species, but they are little known.
- By the way of setting the signals are divided into regular and irregular. The former are deterministic data transfer methods that are defined by an analytical function. Random ones are formulated at the expense of probability theory, and they also take on any values at different time intervals.
- Depending on the functions that describe all the parameters of the signal, the data transmission methods can be analog, discrete, digital (a method that is quantized in level). They are used to ensure the operation of many electrical appliances.
Now the reader knows all types of signal transmission. It’s not difficult for any person to understand them, the main thing is to think a bit and remember the school physics course.
What is the signal processed for?
The signal is processed in order to transmit and receive information that is encrypted in it. Once it is removed, it can be used in various ways. In some situations, it is 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.
In analog and digital signals, special methods are used. In particular, filtering, convolution, correlation. They are necessary to restore the signal if it is damaged or has noise.
Creation and formation
Often, for the formation of signals, analog-to-digital (ADC) and digital-to-analog (DAC) converters are required . Most often, they are both used only in situations with the use of DSP technologies. In other cases, only the use of the DAC is suitable.
When creating physical analog codes with the further use of digital methods, they 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 completely depends on the work and performance features. We are talking about both music tracks and ordinary dialogues between people. If we take, for example, a speaker 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 method of transmitting data. Its disadvantage is the presence of noise, which sometimes leads to a complete loss of information. Such situations very often arise that it is impossible to determine where in the code important data is, and where are ordinary distortions.
It is because of this that digital signal processing has gained great popularity and is gradually replacing analog.
Digital signal
A digital signal is a special data stream, it is described by discrete functions. Its amplitude can take a certain value from those already set. If the analog signal is able to arrive with a huge amount of noise, then the digital filter out most of the received noise.
In addition, this type of data transfer transfers information without unnecessary semantic load. Through one physical channel several codes can be sent at once.
Types of digital signal do not exist, since 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.
Digital signal application
What is the difference between a digital electric signal and others? By the fact that he is able to perform complete regeneration in the repeater. When a signal having the slightest interference enters the communication equipment, it immediately changes its shape to digital. 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 large distortions, then, unfortunately, it cannot be restored. If we take the analog connection in comparison, then in a similar situation the repeater can extract some of the data, spending a lot of energy.
When discussing cellular communication in various formats, it is almost impossible to talk on a digital line with strong distortion, since words or whole phrases are not heard. In this case, analog communication is more effective, because you can continue to conduct dialogue.
It is precisely because of such malfunctions that the digital signal is generated by repeaters very often in order to reduce the line break.
Discrete signal
Now everyone uses a mobile phone or some kind of “dialer” on their computer. One of the tasks of devices or software is the transmission of a signal, in this case a voice stream. For the transfer of a continuous wave, a channel is needed that would have the highest level throughput. That is why a decision was made to use a discrete signal. It does not create the wave itself, but its digital form. Why so? Because the transmission comes from technology (such as a telephone or computer). What are the advantages of this type of information transfer? With its help, the total amount of transmitted data is reduced, and batch sending is also easier to organize.
The concept of "discretization" has long been consistently used in the work of computer technology. Thanks to this signal, not continuous information is transmitted that is fully encoded with special characters and letters, but data collected in special blocks. They are separate and complete particles. This encoding method has long faded into the background, but has not completely disappeared. With it, you can easily transfer small pieces of information.
Comparison of digital and analog signals
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 become clear that analog technologies are losing demand, because their use is irrational. In exchange comes a digital connection. You need to understand what is at stake and what humanity is refusing.
In short, an analog signal is a method of transmitting information, which involves the description of data by continuous functions of time. In fact, 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.
Moving from theory to practice, it must be said that the analog signal is characterized by interference. There are no such problems with digital, because it successfully “smooths” them. Due to new technologies, this method of data transfer is able to restore all the original information on its own without the intervention of a scientist.
Speaking of television, we can already say with confidence: the analogue transmission has long become obsolete. Most consumers switch to a digital signal. The minus of the latter is that if any device is capable of receiving analog transmission, then the more modern way is only a special technique. Although the demand for an outdated method has long fallen, still these types of signals are still not able to completely leave everyday life.