For this huge problem of underwater communication, when the project team reported to Duke, Duke also felt a little helpless.

The most commonly used long-distance underwater acoustic communication technology in the underwater, although the propagation distance can also reach tens of kilometers, but the underwater acoustic communication uses analog sound wave signals, and the waves, fish, ships, etc. in the ocean are all producing various sound wave noises all the time, which makes the sound field in the ocean extremely chaotic, so the interference factors are far more complex than in the air transmission when the sound waves are transmitted in the seawater.

At the same time, the attenuation of the propagation energy of the sound wave in the water is also much faster than the propagation of the electromagnetic wave in the air, which leads to the narrow bandwidth of the underwater acoustic communication, the applicable carrier frequency is low, and the transmission delay is large, resulting in the efficiency of the whole transmission system is very low, and the signals received under the water are often blurred, and it is extremely difficult to ensure accurate communication for the receiving and decoding processing of the signal receiver.

But now in terms of the principle of this communication technology, Duke basically has no possibility of a short-term breakthrough, and there is no unique technology in Kerry's knowledge base that can make underwater communication convenient and fast. What Duke can do is local enhancement, such as an intelligent analysis engine and a high-efficiency signal processor composed of a new high-speed computing chip, which can greatly improve the bit error rate of underwater acoustic communication at the receiving and processing end, and enhance the ability of the submarine to communicate underwater to a certain extent.

However, these are only partial improvements, and they are still completely unable to meet the needs of the theater joint combat system for the exchange of large data volumes.

"At present, there is only one way to solve the high-speed communication when the submarine dives, that is, the towed buoy antenna, that is, the high-speed communication equipment surfaces to the sea, and the submarine realizes long-distance direct communication with the base, fleet or aircraft through slender cables, in addition, as long as the submarine dives more than 200 meters, even if VLF ultra-long wave communication is used, the submarine can only unilaterally receive extremely limited information." Professor Yu Deming, a submarine communication technology research expert from the Naval Submarine Academy, introduced Duke as an expert in the overall group of the Qianlong Project.

"Among the submarines in service in our country, the most widely equipped is the T-HU80 buoy antenna, which can be used by the submarine at a diving speed of 8 to 10 knots when diving 200 meters, with 15 watts of power to communicate with external bases, fleets or aircraft through six preset channels in the HF and UHF bands." Professor Yu Deming continued.

"Although through this aspect, the problem of communication in the submarine submarine state is solved, but at the same time, this communication method easily exposes the location of the submarine to the enemy, and the enemy is completely able to track and locate the submarine through this communication signal, so that the submarine loses the greatest stealth characteristic, which not only greatly reduces the suddenness of the submarine attack, but is also very likely to bring disaster to the submarine.

Therefore, under normal circumstances, submarine units practice radio silence and do not turn on radio communications at will, especially nuclear submarines, which basically unilaterally receive extremely limited information on the enemy's situation and orders transmitted by the bases. The flame of hope that Duke had rekindled was quickly extinguished by Professor Yu Deming's words.

"Professor Yu, in terms of your research, what are the main ideas to solve these problems?" Duke asked modestly that he had little technical accumulation in this world problem in terms of submarines.

"Dean Du," Professor Yu Deming said with some shame after smiling bitterly, "among the plans we once considered, after research and experiments, they are basically rejected now. Because there is actually a huge paradox to solve this problem, on the one hand, we need to use a technical method that can be transmitted over a long distance on the sea surface in order to disseminate information, and on the other hand, this communication method that can be transmitted remotely will inevitably be intercepted by the enemy and expose the submarine target.

Under the current technical conditions, no country, including the United States, has a good solution to this. The towed buoy antenna is the best solution at present, because it can be used in the mobile situation, there is a certain difficulty for the enemy to locate the specific location of the submarine, to a certain extent, this communication mode better takes into account the problems of communication and security.

Of course, due to the limited speed of submarines under water, once the communication is detected by the enemy detection system in this way, they can still greatly narrow and lock the range of activity of the submarine, so that it is still quite dangerous for the submarine operating near the enemy, because anti-submarine aircraft and anti-submarine helicopters can conduct a large area of rapid search, and it is difficult for such a range of activities for submarines to escape the enemy's search. As an expert who has studied this field for decades, Professor Yu Deming is well aware of the advantages and disadvantages of various submarine communication technologies.

Once the communication is activated, the target will inevitably be exposed, so that the submarine will lose its greatest support. However, if communication is not activated, there will be no real coordination between submarines operating in the same theater of operations, and the combat power will be used intensively to attack the most valuable targets in the theater, so that the efficiency of the use of combat power of the submarines in service will not be greatly improved.

For the next few days, Duke was immersed in this question, and in the eyes of Duke's family, Duke looked a little in a trance and couldn't give up, "Duke, have you encountered a problem again?" Shu Ya saw that Duke was not in a good state of mind these days, and asked with concern. On weekdays, Duke will get into it when he encounters a problem, usually busy looking for all kinds of materials or conducting endless experiments, but Shu Ya rarely sees Duke helpless and does nothing.

"Well, there's a question I really can't figure out, you don't have to worry, I'm fine." Duke replied. "I don't have an idea to solve this problem now, and I can't find a direction to work on at all."

"Then take a break." Shu Ya smiled and comforted. "Relax, maybe it will be a flash of inspiration, and you have to relax when you do research, anyway, my son has been arguing to go to Ocean Park for several days, so we might as well take him to Ocean Park to play together, and you can relax and relax."

Before Duke could say yes, the son on the side was already clapping his hands happily, "Go to Ocean Park!" Dad, I'm going to see a dolphin show! ”

Looking at his son's appearance, what else could Duke say.

It's just that Duke is now the highest level of security in China, even if it is a small trip, it must have a large number of people in front of and behind, and at the commanding heights of the buildings near the park, people must be sent to clear and control the scene in advance, so even if Duke agreed to accompany his son to watch the dolphin show, he waited for more than an hour for the security personnel to complete the security layout before he could travel.

Such troublesome preparations are the biggest reason why Duke would rather choose to live in seclusion or go to some remote places on weekdays. But the security team responsible for Duke's security really can't expect Duke to be as lucky as last time after the attack, so they must nip the threat in the bud.

It's just that when Duke saw his son's joy when he watched the dolphin show, he felt that it was worth it today, so his mood gradually began to relax, and he laughed with his son for the wonderful performance of the dolphins, there are 4 dolphins performing in the aquarium today, and the animal trainer led these smart dolphins to perform a lot of coordinated actions, compared to a dolphin performance, this kind of group performance is obviously more difficult, but in the eyes of the audience, the ornamentation has also been greatly improved, only to listen to the audience in the exclamation of the sound constantly, Just know how fascinating these dolphin performances are.

"Dad, when I grow up, I want to keep a large group of dolphins in the family pool to play with me," Duke's son said with excitement, "You see they can jump together in a row, if I raise a large group, it will definitely be more fun, and I can ride dolphins to swim around in the water, how fun." ”

"Good son, dolphins are not so easy to raise, you see such a big one, it takes a very large pool to raise it, and our swimming pool is enough to raise one, let alone raise a group." When Duke heard his son say this, he couldn't help but laugh. Suddenly, Duke's heart moved, as if he had grasped something in his mind, and his body froze there motionless, as if petrified.

Looking at Duke's appearance, Shu Ya, who had been watching the two fathers and sons having fun next to him, hurriedly pulled his son over and asked Duke to continue thinking about him. Although Shuya doesn't know what Duke is thinking about now, this situation is usually Duke's moment of inspiration, and at this time, Shuya's most important thing is not to let her son disturb him.

"A school of fish? Fish? Duke muttered the two words, an idea coming to his mind, but it was still veiled all the time, and it was almost a little bit. He was thinking about his own thoughts here, and he didn't even notice when his son had been quietly pulled aside by his mother and didn't talk to him.

Although the audience was still cheering at the dolphin show, Duke was so immersed in his own flash of thought that he almost forgot about the world in front of him. After a long time, Duke finally grasped this illusory idea.

"Fish? Bait? That's right, school of fish bait! Suddenly, Duke slapped his thigh, and a new idea spurted through his head. To be honest, although Duke's new idea is technically difficult, it is not impossible for Duke to solve and realize, and through such a new idea, it has opened a new window for solving the world-class problem of two-way high-speed communication and submarine concealment of submarines.

(There is a shift after 11 p.m.) ）