Chapter 1015 The key to the two-way data link!
After all, Wu Wei is an old engineer who has been immersed in the field of communication technology for many years. Although he was initially confused by the new term coined by Chang Haonan, there is no obstacle to understanding the concept mentioned by the latter. .
Logically speaking, the next step is to find ways to mitigate or even eliminate the self-interference effect caused by broadcast characteristics.
It’s just...this problem is indeed quite special.
Because in most cases, self-interference will only appear in wireless multi-hop networks.
Just like the previous rounds of testing.
But in actual applications, since you have set up one or more relay stations between point A and point B, it means that the signal sent from A cannot be transmitted to B stably.
There will be no strong self-interference phenomenon.
In other words, the last set of tests just now are closer to reality.
So Wu Wei immediately told Chang Haonan his thoughts.
The latter did not answer immediately, but just lowered his head and thought while pacing around Car No. 1.
In fact, although Wu Wei knew that Chang Haonan wanted to develop network coding technology, he did not know what he ultimately wanted to do.
After all, this matter is more serious, and it also involves the anti-aircraft carrier system, a big killer.
Although the other party's confidentiality level is not low, the fewer people who know, the better.
From the perspective of Wu Wei as a ground relay, what he said is indeed correct.
But satellites, especially low-orbit satellites, are different.
It is not like a car or an airplane that can move wherever it wants, but can only move according to a specific orbit and cycle.
This means that it is inevitable that multiple satellites will come together, or the two satellites that are directly transmitting data are constantly getting farther apart, and a relay satellite needs to be connected in advance for backup.
So, for Chang Haonan, the self-interference problem must be solved.
“That’s it, Comrade Wu Wei.”
After circling the car for an unknown number of times, Chang Haonan finally stopped in front of Wu Wei:
"What you just said does make sense, so the research and development of this satellite/scatter communication vehicle is According to the original plan, the current network coding algorithm will be integrated first, so that at least the information pilot units can have something to use. "
"But in the long run, the scope of application of this technology is limited. It will only be limited to military encrypted communications, but sooner or later it will be expanded to industrial and even civilian fields. Therefore, while continuing to advance the project progress, some resources must be allocated to avoid the impact of self-interference on data transmission. "
Such a compromise plan is naturally not difficult for Wu Wei to accept.
He immediately nodded in agreement, and then asked Chang Haonan about his ideas for solving the problem:
"Chang is always ready to continue to develop new algorithms?"
The essence of self-interference is that the receiving station cannot identify the same content signal source sent by different sending stations, so as long as it can be distinguished at the data level, This trouble can be fundamentally circumvented.
So in Wu Wei's view, algorithm giants like Chang Haonan are likely to have thought of specific technical solutions.
However, Chang Haonan gave a negative answer:
“This problem may be difficult to solve by relying on algorithms alone...”
"The basic function of a relay station, even one with encoding and decoding functions, is to ensure that the information content does not change during the transmission process. Therefore, the solution at the software level may only focus on the transmission sequence..."
< br>“But the throughput of relay communication is already tight. After adding network coding technology, the relay unit is required to have higher computing power... If the transmission sequence is rashly adjusted during the signal transmission process, it will not be easy to improve. I'm afraid the performance will drop again..."
Wu Wei was speechless for a moment.
After being silent for a while, his eyes suddenly lit up:
“Can we start with the hardware and specially design the receiver, such as A to B to C to D? In a multi-hop network, if we let D block the signals from A and B at the physical level and only accept those sent by C, wouldn’t the problem be solved? ”
These words made Chang Haonan's eyes reveal a hint of surprise...and appreciation.
Being able to come up with a completely feasible project plan in such a short period of time without any prior preparation shows that Wu Wei, as the backbone of the 54th Division, does have something. He nodded slightly and said:
“This is indeed the most intuitive and effective method.”
Wu Wei was a little disappointed when he suddenly received such a high evaluation. React:
"Then what you mean is...according to this idea..."
Thinking that the solution he inadvertently proposed might be adopted, he even felt a sense of unreality.
Then, Chang Haonan gave me a bucket of cold water:
“But this method is not flexible enough, and it will also increase the complexity of the system, so... currently I Prepare to use this as a cover-up plan."
"Uh..."
The excited expression Wu Wei had just shown froze on his face.
Chang Haonan was also a little amused by the other party's reaction and explained:
"If you think about it, originally my four stations ABCD can transmit and receive relays in any order, but according to the After the modification as you said, it can only be transmitted in one direction in the order of A-B-C-D... This is only the case of four nodes. If there are more intermediate nodes involved in the whole process, the waste of hardware will be more serious... …”
“Hiss——”
Listening to Chang Haonan’s description, Wu Wei couldn’t help but take a breath of air.
Fortunately, the evening in the desert area was already cool, so the former did not feel that the surrounding temperature had dropped due to this.
"Mr. Chang, are you... planning to establish a two-way data link for sea, land and air?"
In almost a few breaths, Wu Wei keenly guessed it Chang Haonan's purpose... is one.
Although it is only superficial.
“In the long run, yes.”
Regarding the data link, Chang Haonan has sent cooperation invitation letters to many units, so there is no need to hide it.
However, except for Academician Wang Xiaomo, who had foreseen it for a long time, and Wu Wei, who had just been informed, everyone else subconsciously thought that he was just planning to establish an air force, or at most a comprehensive command system for the three services. .
Since it is a command, it is only a one-way communication between superiors and subordinates.
But Chang Haonan really likes what Mr. Ma Weiming said -
If we want to do it, we must surpass the United States!
Therefore, even if the current conditions are not met, he is still prepared to leave room for upgrades to the asymmetric two-way data link in the future.
"Since the software level cannot solve it, the hardware level will bring other problems...Do you have a third route?"
After recovering from the shock, Wu Wei quickly brought the topic back to the self-interference issue discussed earlier.
“The third route is of course impossible.”
Chang Haonan shook his head and said with a slightly helpless tone:
"But I never said it can't be solved at the hardware level..."
"Huh? Then you just..."
"What I just said is that there is a problem with the method you proposed. Don't expand the problem to the entire hardware level."
Chang Haonan glanced at Wu Wei and said in a joking tone.
“Ahem——”
Wu Wei suddenly felt that there was an unhealable crack in his fragile heart...
Chang Haonan finally stopped trying to hide his feelings:
"My idea is, instead of racking my brains to avoid the consequences, It is better to treat the signals sent by other transmitters as useful information, thereby further improving the throughput of the entire multi-hop communication system based on network coding technology! ”
(End of this chapter)