A coding technique commonly used in digital transmission, where logic 0 is represented by an empty level and logic 1 is represented by alternately reversed positive and negative voltages. AON All Optical Net means that the signal channel in the network until the end user node still maintains the form of light, that is, the end-to-end all-optical path, there is no photoelectric converter in the middle.
copy, the whole phrase is copy that, but it is generally said simply to copy, which means "I heard you" or "I und.erstand ", and he agrees, and is also commonly used, "Roger", "Roger that", which is what I heard and I understand.
The abbreviation FM commonly used in English is called frequency modulation - radio, which literally means "frequency modulation - radio" in Chinese. This acronym is mainly used to describe the frequency modulation transmission method in radio communication technology. In the medical field, especially in British medicine, it is relatively popular and is numbered 133. FM belongs to the category of medical abbreviations.
Today, CW English still has some influence among amateur radio communication enthusiasts. By distinguishing itself from traditional forms such as digital, video, etc., CW English communication skills are considered standard skills for amateur radio operators. CW English skills will help a new amateur radio enthusiast quickly get to know other amateurs.
In physics, range can refer to the range or range of a certain physical quantity, such as temperature range, frequency range, and so on. For example, in radio communication, we might talk about the frequency range or wavelength range of a certain radio signal. In computer science, range is also commonly used to describe a continuous sequence of values or characters. For example, in the Python programming language, we can use the range function to generate a sequence of values.
The "Regulations of the People's Republic of China on the Division of Radio Frequencies" stipulates that the frequencies that can be used by amateur services are: 1800-2000khz. 3500-3900khz. 7000-7200khz. 10100-10150khz (minor). 14000-14350khz.
Four 1000 to 1350 MHz: This is the 20 meter amateur radio band, the low end of 100kHz is used for CW (constant amplitude) and RTTY (telex), and the rest of the frequencies are used in USB (upper band) mode.In the United States HAM cannot use SSB (single sideband) below 14150 kHz. The best reception times are daytime and evening.
MHz (FM) Amateur radio Main bands: 80 m 3500~3900 40 m 7000~7100 (LSB) 20 m 14000~14350 15 m 21000~21450 10 m 28000~29700 1180MHz is BY NET frequency, starting from 8:00 every day, often old amateurs. 1330MHz is CRSA NThe symbol "0" corresponds to the modulated waveform of the carrier frequency f1, while the symbol "1" corresponds to the modulated waveform of the carrier frequency f2 (a different carrier frequency from f1), and the change between f1 and f2 is instantaneous.
ASK signal Modulation signal: single-stage non-return-to-zero rectangular pulse train. 1 code, output carrier Acosω0t; 0 code, the output carrier is 0. FSK signal: The use of digital baseband signal to control the frequency of the carrier to transmit information. For example, a code 1 is transmitted with a 1, and a code 0 is transmitted with a 2. It can be regarded as the sum of two interleaved ASK signals.
FSK is frequencyShort for shift keying modulation, that is, different frequencies are used to represent different symbols. For example, 2KHz represents symbol 0 and 3KHz represents symbol 1. GFSK is short for Gaussian frequency shift keying, which uses a Gaussian low-pass filter to limit the spectrum width of the signal before modulation. "Amplitude Shift Keying", also known as "amplitude shift keying" (ASK), is a common way of modulation technology.
The so-called FSK is to use a digital signal to modulate the frequency of the carrier. If the binary modulated signal is used, it is called 2FSK; Adopt moreA base-modulated signal is called MFSK. l modulation method: 2FSK can be regarded as the sum of ASK modulated signals of two different carrier frequencies. l Demodulation methods: coherent method and non-coherent method. l Type: Binary frequency shift keying (2FSK), multi-digit frequency shift keying (MFSK).
In the field of information transmission, FSK, or frequency shift keying, is a long-established and widely used modulation method. It has the advantages of simple implementation, good anti-noise and anti-attenuation performance, especially suitable for medium and low speed data transmission. FSK works by using a digital signal to the carrier frequencyRate modulation, such as 2FSK, can be seen as a superposition of two ASK signals of different carrier frequencies.
Screen bright line wireless charging fsk, bright band or dark line this problem, generally LCD screen wireless charging fsk fault. The bright line fault is generally a problem with the line connecting the LCD body or the driver IC of a row or column is damaged. The dark line is generally the body of the screen has leakage, or the TAB flexible plate connection is open. The above two problems are basically a death sentence to the machine, there is no maintenance value, because the price of a screen is too high.
Hello, I am very pleased to explain to you that the current wireless transmission technology in the field of smart home mainly has the following wireless charging fsk : Power line carrier technology: mainly including X-10 and PLCBUS, in China's power gridThe environment is complex, and the clutter interference on the power grid is serious in the environment, the operation state is difficult to ensure stability, especially in office buildings, commercial buildings and other places are very easy to be disturbed by high-power electrical appliances; Not suitable for large-scale applications.
Compared with the bus smart home system, the advantages of wireless are plug and play, no wiring, etc. But the mainstream Wi-Fi, ZigBee, Bluetooth in the home environment have their own shortcomings. There are a lot of technical introductions on the Internet, I will not analyze the technology in detail, from the application to talk about. Wi-Fi is a communication protocol based on IEEE8011, which is widely used in smart phonesProducts and smart home appliances.
Z-Wave technology is one of the low-power wireless technologies commonly used in the field of smart home. It realizes the networking of home devices by installing Z-Wave modules in the room, thus achieving intelligent control. Compared to Wi-Fi technology, Z-Wave technology enables more accurate control of home devices, and is a low-power and efficient technology. Zigbee Wireless technology Zigbee technology is also a low-power wireless technology for smart home device communication.
Lora is also a very hot wireless communication technology recently, a collection of doubleTo communication, wireless anti-interference ability is strong, automatic frequency modulation to avoid congestion, communication distance is far, power on communication and other advantages, the subsequent application in the smart home will certainly be more and more, the development at this stage is also subject to the module cost is too expensive, the volume is too large, the network encryption communication system is not perfect and other factors have not been large-scale application.
Intelligent convenience is convenient, but the price is too high to accept although the current domestic smart home market is beginning to take shape, but the consumption of smart home is still a relatively wealthy family can afford to consume. The smart home that families now pursue is just a few individual products, whileDoes not constitute the entire smart home system, the cost of the initial installation is already a small investment, but the later maintenance is a bottomless pit.