Shulou(Shulou.com)11/24 Report--

In a person's temperament

There are roads, books, and loved ones.

What stories did 5G go through?

An introduction to a high-definition movie can be downloaded in a second.

Remote games will no longer feel stuttered or delayed.

Relying on 5G, there are also a series of new things, such as car networking, autopilot, remote control and so on.

Where did 5G come from?

What kind of story did she go through to get to where she is now?

This issue will analyze in detail the development process of wireless communication and how it has developed to such a popular 5G.

The word 1G1G has been around for a long time, and the post-90s basically have no idea about it.

But it did take the first place in the history of wireless communications.

I have heard such a saying that no matter what industry you work in, you can either be the first one or the best one.

But often the first one with high probability is not the best one.

The same is true of 1G. Looking back, compared with the current 5G, the first generation of wireless communication is simply weak.

How weak is it?

First, let's take a look at the representative of 1G, or the jianghu elder brother, who was briefly introduced in the previous article.

Look at this look. Look at this head.

Only a big brother like this can afford to use it.

When does a guy with such a big head stand up bigger than his head?

It's really worthy of the title "Big Brother".

This guy doesn't support texting, surfing the Internet, video, etc., and can only be used to make a phone call.

Why?

It's very simple, because the function of the eldest brother is not supported (this is nonsense)

It is true that the function does not support it, but even if the big brother function supports it, the wireless signal does not support it.

Why is that?

Because it is still an analog signal, what is an analog signal?

Go straight to the picture.

This picture is a sound wave chart, which is what your voice looks like in the air when you shout.

It's so messy, so complicated.

But there is no shortage of hard-working people, chaos is chaos, do not delay to uncover it

At this time, an old man named Fourier came out of Europe and said:

All the waveforms in the world, no matter how ugly they are, can be given out in a very good-looking mold.

This sentence may seem illusory, but it is the foundation of the whole communication world, including the awesome 5G.

The meaning of the old man is very clear: no matter how ugly it is, it is a stack of good-looking genes.

If you say so, you will feel much more comfortable.

It's not that we are not beautiful, but the beautiful genetic position is on the wrong side, and the beautiful pile is not obvious.

He said again that a beautiful waveform looks like this.

Beauty is really not built, which is much clearer.

The prickly waves with edges in the picture above are also piled up by countless similarly beautiful waves.

The representative of 1G is inspired by sound waves, right?

The continuous beautiful waves of speech are modulated to a higher frequency and transmitted through the antenna above the eldest brother.

The purpose of transmitting information will be achieved.

To put it simply, Big Brother has accomplished such a simple task.

Compared with the beacon fire, this is advanced enough, but the eldest brother also has a fatal problem.

When it was sent out, it looked like the beautiful wave in the picture below.

After colliding with buildings, leaves and walls in the air, it is deformed and becomes prickly in the picture above.

Apparently, the gene that hit the sound was mutated.

What is the effect of a sudden change in the waveform?

The impact is that what is said at this end may be inaudible, inaudible, or even misheard at the other end.

If it is good, it will be bumped into a rascal.

You can't always turn dusk love into cauliflower.

In order to solve this fatal problem, people began to think of ways.

So, 2G made its debut.

So far, 2G2G communication is the most widely used and mature communication.

Some people may say that 4G is also very mature and uses a lot.

But compared with the once brilliant 2G, it is almost hot.

2G is a basic package, and people all over the world can live on hou.

4G is an upgraded package, which is still not available in poor areas and regions.

Once the world's population of 5 billion, 2G mobile phones reached nearly 4 billion, covering all countries in the world, whether poor or rich

Judging from the number of users of the service, 2G is awesome.

From the point of view of communication mode, 2G changes the analog communication mode and opens the way of digital communication.

So it's not too much to say that 2G is a milestone in the communications world.

Why are there so many 2G users?

First, it is the first generation of digital communication system, which greatly improves the fatal problem of being inaudible, inaudible and misheard in 1G analog communication.

Second, the size of the mobile phone is getting smaller, and the price is much cheaper compared with the eldest brother.

Two is enough.

So, what is digital communication?

The numbers are nothing more than 0, 1, 2, 3.

In the current stage, the popular digital transformation in China has changed to simple, and it can not escape the palms of 1, 2, 3.

But for the computer, it only knows 0 and 1, and the other numbers are not familiar.

Because the objects that process signals in communication are also chips, just like computers.

Therefore, in the digital communication system, the carrier of information is only 0 and 1.

By coding speech and text with 0 and 1, the digital transformation of communication is realized.

Can you represent so many things with only zeros and ones? Voice, text, pictures, videos, etc.

The answer is yes, the painting style is like this in the following picture.

Of course, pictures and videos can not be supported in the 2G era, and we can only make phone calls and send text messages.

Encode the words to be said and the messages to be sent into the arrangement of 0 and 1 in the picture.

Different content is represented by different arrangements of 0 and 1.

This is the way to express the encoded 0 and 1 in a graph.

If you encode a sentence into a pile of numbers, there are only two signal states, either 0 or 1.

And in the coding process, also artificially added some supervision of the use of 0meme1

Used to correct possible situations that decode 0 into 1 or 1 into 0

This greatly reduces the probability of being mistranslated.

In addition, only the information represented by 0BI 1 will not be affected by the accumulation of noise and will not stack 1 into 3.

The analog signal is different. In the process of transmission, the noise will constantly change the shape of the waveform. No one can tell what the shape will be.

Therefore, digital communication is much more reliable than analog communication system.

In terms of communication resources, resources can be divided into four areas: time, frequency, airspace and code domain.

There is no airspace at this time, because there is no concept of multiple antennas, which was explained in detail in the previous article.

The code field is the basic coding method at this time, and it has not been deeply developed in this field, and we did not make a big article in this domain until 3G.

Mainly allocate and schedule resources in time domain and frequency domain.

In the figure, the horizontal right is split in time, and the horizontal upward is split in frequency.

After the two cross, there is a small grid.

The zeros and ones mentioned above are sent in these small grids.

Assign a small grid to each mobile phone and make calls in your own cell without affecting each other.

In the diagram: what is 5G? If you compare 5G to five lanes, 4G bandwidth is an one-way lane.

At this time, the carrier width of 2G is only 200kHz, which is 1% of the width of 4G, which is 1/500 of 5G.

No wonder 2G can only be used to send text messages and make phone calls.

In addition, there is no basic base technology OFDM for 4G and 5G at this time, which will be described in the following 4G.

Therefore, in order to avoid interference, the waves in different frequency domain should be separated by gaps.

This will consume some resources, so the utilization rate of resources in the 2G era is low.

And it is far from reaching a high level in the effective use of resources.

Therefore, 2G makes do with it, but what is remarkable is the use of digital technology, and its reliability has been greatly improved.

I can hear the phone much more clearly, and I can support texting.

The important thing is that the number of cauliflower incidents has decreased a lot, which can be regarded as a model of being beautiful and doing good deeds.

With the development of communication, it can basically satisfy long-distance communication, but people's desires are always unlimited.

Not satisfied with making phone calls and texting.

Therefore, began a new exploration (toss) journey

3G debut

The development of 3G communication from 1G to 2G has increased people's posture and tasted the sweetness of the development of science and technology.

Therefore, people continue to explore the unknown world.

In other words, people never stop exploring the unknown.

Since the time and frequency domain have been clearly divided into a small grid

There are no breakthroughs in these two fields for the time being.

As for the airspace, people's field of vision has not yet been opened, and the performance depth of multiple antennas is not known.

Therefore, at this time, the research focuses on the code domain.

Let's go back to the nature of communication: it's just passing the message to the person you want to deliver.

The more messages per unit time, the better.

In that case, there are only two goals:

1. Increase the resources for effective communication, that is, the width of the road

two。 Reduce the interference of other signals

The improvement of 3G performance only starts from these two aspects.

First, the bandwidth is broadened, which is the most direct way and the easiest to think of.

If you want to run more cars on the road, the most direct way is to make the road wider.

The maximum transmission bandwidth of 3G has been increased from 2G 200KHz to 5MHz, an increase of 25 times.

Second, great changes and deep digging have been made in the code field.

Go straight to the picture.

2G communications are divided into a lot of small boxes, and everyone makes phone calls in their own grid.

It's like talking in pairs in a single room, bedroom or toilet, and the different rooms don't affect each other.

Although each other's rooms do not interfere with each other, the problem is to use 2G to make phone calls, which is divided into three steps.

Build several small rooms first.

Assign people to it

Finally, close the door of the room

How troublesome to say, when it comes to 3G, it will simply dry up the small room.

If you have something to say, just talk about it in the hall. Don't go quietly into the small room.

When so many people talk in pairs, they will interfere with each other. Isn't it impossible for them to have a whisper?

What shall I do?

When it comes to encrypting cool techs, people are still very smart, and it's not enough for different people to talk to each other by stipulating that they speak different languages.

The painting style is like this.

Talk in the same hall, but different groups use different languages

Then there will be no interference with each other.

It's a beautiful move, too.

That is to say, with the increase of the bandwidth, the space in the hall must be much more spacious than the small single room (expanded 25 times).

Interference between different conversations can be reduced by using different languages

The two main problems mentioned above have been solved or alleviated.

But the interference is still not completely solved.

Imagine two people whispering in Shaanxi dialect, and a third person broadcasting in Henan dialect next to them with a loudspeaker.

Although the language features are obvious, the whisper is still inaudible.

Fell into the pit of cauliflower again.

Therefore, 3G system is a self-interference system, mobile phones in the same community.

The ones with higher power will drown out the signals with less power.

In addition, if the water is shallow, the eldest brothers will scramble for territory and will interfere with each other all the time.

What shall I do?

It's time for the motivational protagonist to make his debut:

During World War II, there was a beautiful woman in Austria named Heidi Rama, who was a real movie star.

At that time, allied torpedoes were always accurately intercepted to attack fascist warships.

Because Adolf's wolf pack submarine can accurately capture the command to fire the torpedo, thus knowing the direction of the torpedo in advance.

When the beautiful woman practiced the piano at home, she was greatly inspired.

If the instruction jumps like a piano key, it will not be easily tracked by the other party.

Jumping and sending signals can alleviate the problem of being interfered / tracked all the time.

After a try, it really worked, and the success rate of attacking the target was greatly improved.

This is the frequency hopping technology that shines brilliantly in 3G and WiFi

Cross-discipline is easy to bear fruit, does it start with her?

Look at other people's open life, there are not only beautiful skins, but also beautiful flesh.

The introduction of so many new gadgets does improve the performance of communications.

Therefore, the 3G era can support multimedia.

Was

But at this time, watching the NBA game is just by constantly refreshing the web page and watching the real-time results.

Looking at a GIF picture and browsing a novel online can still be supported.

But it still can't compare with the visual impact of the video.

As a result, people began a new road of exploration.

The familiar protagonist 4G begins to debut.

At this stage of the development of 4G communication, it has reached the boundary that we are all familiar with.

4G, what a fresh word, the young fresh meat only began to enter people's eyes in 2014.

In just a few years, by 2020, the total number of 4G users in China has reached 1.2 billion, accounting for more than 80% of the total mobile phone users.

It's so hot, what new ways have people come up with it?

Let's take a look back at 3G. All the people are talking in the same hall. Although they use different languages, they can still dance and spread the frequency.

However, the self-jamming system is naturally still a jamming system, and there will still be hard interference.

Therefore, 4G can not continue to study on the basis of 3G, and there is basically no future.

After a lot of research, people decided that 4G should build the small room that 3G knocked down again.

So it's back to the days when there were cubicles.

This is the law of the development of things, and sometimes there are inevitable setbacks in the process of progress.

Do you still remember the two breakthroughs of promotion?

It must be to build and widen the road again.

You are right. 4G has widened from 3G 5MHz to the maximum bandwidth 20MHz.

The road is four times wider.

After seeing the analysis of the last article, it is easy to improve dozens or even hundreds of times, and four times is really nothing.

Take it easy

In addition to opening up the road, 4G is also tossing about in another domain, which is the latest to debut-- airspace.

Start working on multiple antennas, in the illustration: what is 5G? If an antenna transmits all the data

Then eight antennas can transmit eight channels of data at the same time, is that what it means?

The mobile phone has got two antennas, which can send up to two channels of data, and the base station has eight antennas that can transmit eight channels of data at the same time.

And the above four times the bandwidth increase, multiplied together, compared with 3G also has dozens of times

In addition, it is upgraded from 1G frequency division multiplexing-- FDM to OFDM.

Multi-antenna + OFDM has directly become the technical base of 4G and 5G.

See, the picture below is FDM, and the one above is OFDM.

Not only do we lose the partition between different waves.

Can different waves overlap and not interfere with each other?

When it's done, there's really no interference.

Because the highest and lowest point of this wave is exactly at the point of 0 of the overlapping wave, 0 certainly has no effect on the others.

Because there are only 0 and 1 in digital communication, so as long as you know the high and low waves, it is not necessary to know the specific values.

How did it end up like this, or the old European man named Fourier mentioned above did a good thing to the end and found a way to deal with it?

Because the implementation algorithm is more complex, after some mathematical transformation, it will not be expanded here, and we will talk about it in detail in the future.

In this way, a proper performance improvement of dozens of times will come out.

With this tens of times performance increase, 4G can finally watch video.

Of course, 4G has improved so much that it can not only watch video, but also the mobile Internet has taken off on this basis.

Wechat, Alipay, bicycles, online ride-hailing, etc., are now basically one machine in hand, just go.

The mobile Internet industry with 4G technology creates trillions of values every year.

With the development of mobile communication to 4G, we have finally seen a big explosion of output value.

From 1G research to 4G research has gone through 30 + years, the development of everything has to go through a long process.

The desire for quick success and quick profit achieved overnight is against the objective law.

As can be seen from the above review, each generation has studied its own set of things.

It's not a slap on the head, it's not a whim, it's a real study.

With the development of 4G, it can meet all the needs of people's life.

However, seeing that wireless technology can create so much socio-economic value

People began to focus on the use of wireless communication technology to transform the industry, in order to create greater value.

5G just walked into people's field of vision.

5G first briefly look forward to what 5G can do.

Go straight to the picture.

The functions that can be supported by 5G are divided into three major scenarios.

Enhanced mobile broadband: continue to improve the quality of people's lives on the basis of 4G

Massive machine communication: for the outbreak of the Internet of things

Ultra-high reliability and low latency: for special scenarios, such as industrial control, vehicle networking, remote control, etc.

For the first item, you can send high-definition movies in seconds, or even faster

For Article 2, Internet terminals that can reach millions per square kilometer

For the third item, the communication delay can be achieved in milliseconds.

With 5G blessing, the world will basically become like this.

It is expected that 5G can truly realize the era of information at will, the touch of everything and the Internet of everything.

From 1G to 5G, wireless communication has gone through an extraordinary course of 40 + years.

To sum up, I just want to say three words: it's not easy.

But:

What is readily available is often of no value

On the other hand, it also confirms that the communication, which has been going for such a long time and experienced ups and downs, is destined to be invaluable.

Judging from the mobile phone alone, it is getting smaller and smaller.

But the functions do continue to enrich and develop.

Some people say that 4G has changed society, and 5G will change the world.

Let's look forward to the new world of the Internet of everything in 5G era.

Conclusion this paper makes a detailed analysis of the wireless communication from 1G to 5G, which has experienced numerous ups and downs.

From the analysis of the process of communication development, Baby Zi also realized some other principles.

The development of everything has to go through a series of processes of germination, growth, revision and promotion.

The law of the development of things in accordance with Marxist philosophy

The development of any new thing will not be plain sailing, and we have to experience it.

Development-setbacks-improvement-progress

This is the law of negation of negation, one of the three pillars of Ma philosophy.

In the negation of negation, it is constantly updated to improve.

Things that can be achieved overnight do not exist, but those who make progress will inevitably experience setbacks and short-term setbacks.

It should be noted that the wheel of history moves forward in the mud, not on the highway.

Therefore, it has its inherent rhythm and resilience.

Isn't there something wrong with life?

If you want to plan your life with rhythm, there is no hurry.

Do things with resilience and be impatient.

In Bollywood, Rancho says that if you keep your feet on the ground, success will come with you.

There are also butterflies in China if you are in full bloom.

It all makes some sense.

Or down-to-earth diligence is the king, there may be no short-term profit, but there will be great benefit in the end.

This article comes from the official account of Wechat: Wazi (ID:massive_a)

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