What is a system?

Table of Contents

1. What is a system?

2. Communication system

(1) Analog communication system

(2) Digital communication system

3. Control system

4. Computer system

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1. What is a system?

A system, is a functional whole composed of several interacting and interdependent things.In general, systems cover a wide range of physical and non-physical systems, artificial systems, and natural systems.For example, communication systems, power systems, and mechanical systems can be called physical systems; political structures, economic organizations, and production management are non-physical systems; computer networks, transportation networks, and symphony orchestras are artificial systems; atomic nuclei, solar systems, animal nerves, etc.Networks are natural systems.

We know that Electronic information engineering mainly studies the acquisition and processing of information, the design, development, application and integration of electronic equipment and information systems.Because this article belongs to the column of electronic information knowledge, it focuses on some systems involved in the field of information science and technology, such as communication systems, control systems and computer systems, which are often used for signal transmission, exchange and processing., a number of various systems together form a comprehensive complex whole, such as aerospace systems.

2. Communication system

Communication system: The general term for the system used to complete the transmission of information, generally consisting of a source (transmitter), a sink (receiver) andThe channel (transmission channel) is composed, as shown in the following figure (from Baidu Encyclopedia):

(1) Analog communication system

A communication system that transmits analog messages is called an analog communication system.The core is the modulation and demodulation unit.The structure of a general simulation system is as follows:

Modulation: realized in the time domain, and manifested as a shift of the spectrum in the frequency domain

Demodulation: the reverse process of modulation

(2) Digital communication system

A system that transmits digital signals is called a digital communication system.A relatively complete modern digital communication system is shown in the figure below, in which the white solid line box is an essential part, but the part in the gray dotted line box is optional.

Compared with analog communication systems, digital communication systems can effectively avoid being interfered by noise, which is more conducive to long-distance transmission, and the cost is also lower and easier to implement.

3. Control system

Control system:A management system with its own goals and functions composed of control subjects, control objects and control media (from Baidu Encyclopedia).It can be divided into digital control system and analog control system by the difference of the signal technology used.

4. Computer system

Computer system:A computer system consists of hardware (sub)systems and software (sub)systems.The former is an organic combination of various physical components formed by the principles of electricity, magnetism, light, and mechanics, and is the entity on which the system works.The latter are the various procedures and documents used to direct the entire system to work as specified.The computer system is also more complex, and any subsystem and the composition of the subsystem can be specially studied.