60s researcher

After the two entered, they sat down facing each other. Lu Jian remembered that Director Huo was going out before, and asked quickly: "Director Huo, did you want to go out just now?"

Director Huo nodded with a smile, "The Tsinghua University asked me to go to a meeting. Isn't this the new year's freshmen coming to report? President Xu asked us to go over and discuss the arrangements for the start of the semester, but it's okay, there is still some time, we I can say a few more words."

Lu Jian nodded understandingly. Director Huo is now the dean of the School of Information Science and Engineering at Tsinghua University, so he naturally wants to participate in the work.Lu Jian didn't waste any time, and directly said to Director Huo, "That's it, then our project team will start the mobile phone project next."

Director Huo said seriously: "That's right, you can continue to work on this project. The above funds have been allocated, but the time is limited, you still have to hurry up."

Lu Jian nodded and agreed, "Understood, we will do it as soon as possible, did it say anything about the construction of the base station?"

Director Huo looked at him and smiled, "Are you interested in this?"

"Of course, we have researched this mobile phone, so we can't stop using it, right?" Lu Jian admitted without hesitation.

Director Huo thought for a while, and said to Lu Jian: "This matter is not so easy to handle. The base station construction will cost a lot of money, and the mobile phone has not yet been researched, and there is pressure from above. When the time comes, we will now build a small Base stations, it's better to wait until after the mobile phone experiment."

Lu Jian nodded, this matter really can't be rushed, and we can only talk about it after the mobile phone is researched. "Understood, we will get the results out as soon as possible."

Director Huo is quite confident in him, and smiled, "Okay, then you should show the results earlier."

Lu Jian came here today to talk about research, and now that he has finished speaking, he plans to leave, "Then Director Huo, I will leave as soon as I have nothing to do, and I will not delay your going to Tsinghua University for a meeting."

Director Huo didn't keep him, and there was not much time left, "Okay, then you go back first."

After Lu Jian finished speaking, he left Director Huo's office and returned to his laboratory.

When Lu saw the office, Xu Yan was working in it, and Jian Mingyuan also came over. Lu Jian was a little surprised, "Jian Mingyuan, aren't you still resting at home? Why are you back to work?"

Jian Mingyuan still said in an extremely flat voice: "Today is not the weekend, Duo Duo is not at home, the teacher took Xue Yang to the library, and I came to work if I have nothing to do." It wasn't the first day he came to work Well, Jian Mingyuan is like this these days during the holidays. Unless Duoduo and the others are at home, he always comes to work in the laboratory by himself and sorts out a lot of information.Both sleep and mobile phone related.

Lu Jian was suspicious, "You're not like this all this time, are you? You come to the lab to work overtime every now and then." Lu Jian looked at the notebook on his desk, it was filled with densely packed words, it didn't look like a day or two effort.

Before Jian Mingyuan responded, Xu Yan on the side immediately said helplessly: "Who said no, this idiot, after half a month of rest, he only stayed at home for four or five days, and ran to the laboratory if he had nothing to do." In his words They all hate iron but not steel.

Jian Mingyuan was very calm, since Xu Yan had already helped him answer, there was no need for him to continue explaining.

Lu Jian was also at a loss for words to Jian Mingyuan. Although they had a heavy research task, but this time they took a break this time. How could there be anyone like him.

After thinking about it, Lu Jian said to the two people present: "Since we are all here, let's have a short meeting together and talk about the mobile phone project."

As he spoke, he also found a chair and sat down, holding a notebook in his hand.

Xu Yan and Jian Mingyuan put down what they were doing, sat upright, looked at Lu Jian with both eyes, as if they were in a serious meeting.

Lu Jian thought for a while, and was going to let Jian Mingyuan speak first. After all, he wrote the rough project plan, so the design of the project naturally needed his opinion.

Jian Mingyuan nodded. The project plan he proposed before was the first generation of mobile phone, which used the cellular mobile phone communication system. He was naturally talking about this aspect, "I plan to use the cellular mobile phone communication system. A large and medium-capacity mobile phone communication system in which adjacent small cellular coverage areas form a service area. Information is transmitted using analog modulation...”

"This system should include switching centers, base stations, mobile stations, that is, mobile phones, and transmission phones..."

"The main thing we are going to study this time is the mobile station, that is, the mobile phone, and this piece includes four parts: the receiver, the control component, the antenna, and the power supply..."

Jian Mingyuan said a lot, which are all his ideas during this period. Lu Jian thinks that there are many ideas in it that are relatively good, and they all have a basis for realization, but they are still limited by the current equipment, so there are always some infinities. Satisfactory.Moreover, these mobile phones basically use the frequency division multiplexing method, and can only carry out voice communication, and the signal is very unstable.Moreover, this kind of mobile phone is like a simple radio duplex station. All calls are locked at a fixed frequency, and it is easy for others to eavesdrop on the call content, which is very unsafe.

Lu Jian was a little hesitant in his heart. He wanted to use GSM, which is the Global System for Mobile Communications, but this is the second generation of mobile communication technology. This technology digitizes data and then compresses it. Both user data streams are sent out the channel together.

This technology has many advantages, such as clear calls, strong stability, and it is not easy to be disturbed, and the power consumption of mobile phones is low. Of course, the research of this technology takes a lot of time, but this communication system is for global communication, and the difficulty is not small. .They are still starting from scratch now, and they haven't even researched the first generation of technology, let alone the second generation.

Thoughts were flying in Lu Jian's mind, but Jian Mingyuan didn't have any idea, so he was still concentrating on talking about his own thoughts.

"The above are all my thoughts, and I'm done."

Before Lu Jian could think clearly, Jian Mingyuan had finished his words, and then looked at Lu Jian with his eyes.

After seeing it for a while, Lu came back to his senses. He made up his mind and planned to talk about this technology first. Let's discuss it. As for whether to do it or not, that's another matter. Thinking of this, he said to the two of them: " Analog cellular technology can be done, but this technology also has many disadvantages, such as being easy to be eavesdropped, and the communication effect is not good.”

Hearing what Lu Jian said, Jian Mingyuan didn't mean to be annoyed at all, and asked Lu Jian very curiously: "Do you have any other ideas?" He also talked to Jian Duoduo when discussing the problem It's time to be more positive.

Under the expectant eyes of the other two, Lu Jian nodded, "That's right, I have an idea, my idea is that we skip the first generation of analog phones, and directly study the second generation of digital phones, using GSM Technology, that is, the global mobile communication system directly uses it to use digital modulation technology, and one of the key technologies is time division multiple access, which is a medium for sharing transmission and allows multiple users to use the same frequency in different time slots. I think this frequency should be 900MHZ..."

Lu Jian explained all the detailed techniques he knew, but Xu Yan and the others frowned more and more as they listened. They looked embarrassed and puzzled, as if they didn't understand some of Lu Jian's ideas. Didn't figure it out.Lu Jian talked for a long time, and when he finished speaking, it was almost time for lunch. After he finished speaking, he looked at Jian Mingyuan and Xu Yan with questioning eyes, "The general technique is like this. Is there anything else you don't understand?"

Xu Yan, who was still a little confused, immediately said to him: "What you said seems a bit complicated. It sounds like it is better to keep it confidential, but this difficulty should be much higher than that of analog cellular technology, right? We are so short Can time be successful in research?"

After hearing so much, Xu Yan still doesn't know much about Lu Jianhua's content. He always feels that this technology is quite difficult, and it should not be easy to break through in a short time.

Jian Mingyuan also nodded, "You mean this technology is very good, but our current technology accumulation should not be able to realize it for the time being?" Just one time division multiple access will take a lot of time, how can a year be? can be done.

Lu Jian also knew this, and said very seriously: "I also know that this technology is relatively difficult, but here are the advantages of this technology, and I want to discuss it with everyone. As for which solution to use, After discussing it, we will make a decision."

Xu Yan nodded, "Okay, then let's discuss it first. According to my opinion, I still think it is better to use analog cellular technology first. GSM, that is, the Global System for Mobile Communications, can be the next-generation technology development direction. After all, we still need to use analog cellular technology." With accumulation, lay a foundation, you cannot directly build a castle in the air."

Jian Mingyuan also quickly expressed his opinion, "I also think that it is better to use analog cellular technology with our current technology for the time being. The development of communication technology in our country is still very slow, and there are few talents in this area. We still need to ask for help from others. What do you think? No one should understand for the time being."

Lu Jian was also very helpless, knowing that both of them were right. A mobile phone is not simply a mobile phone. There are many supporting systems and facilities. After making the mobile phone, he still has to teach many people. It's a pity that although he has some understanding of this area, he doesn't know much about it. According to his thinking, there must be no progress in a short time.