Regarding 5G communication, the common articles are all difficult to understand, and I can't bear to look down. I will reprint one article and use 5D to achieve 5G entry.
Simply put, 5G is the fifth-generation communication technology, the main features are wavelengths of millimeters, ultra-wideband, ultra-high speed, ultra-low latency. 1G realizes analog voice communication. Big Brother can only make calls without screen; 2G realizes digital communication of voice communication, and the function machine has a small screen to send text messages; 3G realizes multimedia communication such as pictures other than voice, and the screen becomes larger. The picture is; 4G realizes local high-speed Internet access, big screen intelligent machine can watch short video, but the signal in the city is good, the signal of the old home is poor. 1G~4G is aimed at more convenient and quick communication between people, and 5G will realize the connection of anytime, anywhere, and everything, so that humans dare to expect to participate in the same way with all the things on the earth through live broadcast.
At present, the mainstream 4G LTE has a theoretical rate of only 150 Mbps. This is completely incomparable with wired.
Therefore, if 5G wants to achieve a high end-to-end rate, the focus is to break through the bottleneck of the wireless part.
Wireless communication is the use of electromagnetic waves for communication. Both electric waves and light waves are electromagnetic waves.
The functional characteristics of electromagnetic waves are determined by its frequency. Electromagnetic waves of different frequencies have different attribute characteristics and thus have different uses.
We currently use radio waves for communication. Of course, lightwave communication is also on the rise, such as LiFi.
Radio waves are a type of electromagnetic wave whose frequency resources are limited.
The frequency range of 5G is divided into two types: one is below 6 GHz, and this is not too different from our current 2/3/4G. There is another one, which is very high. At 24 GHz or higher, at present, the international experiment mainly uses 28 GHz.
This is the first technical feature of 5G.
The remarkable characteristics of electromagnetic waves: the higher the frequency, the shorter the wavelength, and the closer to linear propagation (the worse the ability to diffract and penetrate the wall). The higher the frequency, the greater the attenuation in the propagation medium.
You see the laser pointer (wavelength 635nm or so), the light that is emitted is straight, and it will not pass if it is blocked.
Look at satellite communications and GPS navigation (wavelength around 1cm). If there is obstruction, there is no signal.
The satellite's cauldron must be calibrated in the direction of the satellite, otherwise even a little bit will affect the signal quality.
If mobile communication uses a high frequency band, then its biggest problem is that the transmission distance is greatly shortened and the coverage capability is greatly reduced.
Covering the same area, the number of 5G base stations required will greatly exceed 4G.
Under the premise of high frequency, in order to reduce the cost pressure on network construction, 5G must find a new way out.
First of all, it is a micro base station.
There are two types of base stations, a micro base station and a macro base station. Look at the name to know that the micro base station is small, the macro base station is very big!
In fact, there are quite a few micro base stations, especially in urban areas and indoors.
Later, in the 5G era, there will be more micro base stations, which will be installed everywhere, almost everywhere.
So many base stations are around, will it affect the human body? will not.
In fact, contrary to traditional cognition, in fact, the more base stations, the smaller the radiation!
In millimeter wave communication, the antenna also becomes millimeter.
This means that the antenna can be completely inserted into the phone, and even a lot of roots can be plugged.
This is the third biggest killer of 5G -
MIMO is "Multiple-Input Multiple-Output", multiple antennas are transmitted, and multiple antennas are received.
In the LTE era, we already have MIMO, but the number of antennas is not too large, it can only be said to be the primary version of MIMO.
In the 5G era, MIMO technology continued to flourish, and now it has become an enhanced version of Massive MIMO (Massive: Massive, Massive).