pam4 modulation

Broadband access technology is still quite common, so I have studied the two new broadband access technologies that are currently emerging. I would like to share them with you here and hope they will be useful to you. In the past decade, two new modulation and demodulation technologies, Cable Modem and ADSL Asymmetric Digital user line, have emerged. Cable Modem implements data transmission up to 10 mbH/s on a hybrid optical fiber/coaxial network (HFC

With the continuous development of the Communication Industry, broadband access technology is constantly being innovated. Here we will introduce two new access technologies and make a detailed comparison, I believe that the access industry will develop better in the future. In the past decade, two new modulation and demodulation technologies, Cable Modem and ADSL Asymmetric Digital user line, have emerged. Cable Modem implements data transmission up t

radio technology, you can use an average power less than 1 MW to cover a few miles, or even use a low-gain antenna. It is particularly valuable that it has low Interference Characteristics and strong multi-path interference resistance to other wireless systems. It is easier to implement than to build a common spread spectrum system, with a low cost. It is precisely because of the above features that the UWB communication technology has been widely used in personal communication, intra-building

standards. 802.1lb uses the KNN modulation technology to increase the data transmission rate, up to 11 Mbit/s. However, if the transmission rate exceeds 11 Mbit/s, it is very difficult to implement a more complex balance and modulation function to combat multi-path interference. Therefore, in order to promote the development of the wireless LAN, The 802.1l Working Group also introduced 0ofdm

RFID (Radio Frequency identification): A tutorialcontents: Introduction to Radio Frequency Identification-rfid What is RFID Compare RFID with Bar Code technology Benefits of RFID Disadvantages of RFID Active and Passive RFID Systems RFID Frequencies Operation of RFID Systems RFID Building Blocks RFID Tag block schematic, and operation Backscatter modulation RFID Standa

Pulse width modulation (PWM) is the abbreviation of English "Pulse width modulation", referred to as pulse width modulation. It is a very effective technology to control analog circuits by using digital output of microprocessor, which is widely used in many fields such as measurement, communication, power control and transformation. A simulation control mode, ac

segment, wide bandwidth, high speed, high spectrum utilization: With the diversification of user business, especially broadband, the information rate of the past Kbps or more than 10 kbps is not enough, many users require dozens of Mbps information rate. To improve the information rate, in addition to the use of advanced duplex technology, coding technology and modulation technology, the most basic is the wider channel bandwidth, the corresponding ne

adjustment unit can quickly track the channel change and adjust the rate by adopting different coding modulation schemes. When the channel condition is better, the Hs-dsch adopts a more efficient modulation method--16QAM to obtain higher frequency band utilization. Theoretically, although the XQAM modulation method can improve the channel utilization, but becau

Study on the Influence of optical fiber nonlinear effects on optical OFDM signals (1) Optical Orthogonal Frequency Di-vision Multiplexing (O-OFDM) is a new type of Optical transmission technology that has been developed in recent years, it applies Orthogonal Fre-quency Division Multiplexing (OFDM) technology to optical fiber channels. Transmitting OFDM Signals in optical fiber channels can improve the spectrum utilization and resist dispersion and various noise interference, with higher transmi

IntroductionThe PDM represents the pulse density modulation. However, a better abbreviation is "1-bit oversampling audio" because it is simply a high-sample-rate, single bitrate digital system. If you are looking for an advantage, it is that the sample rate is several times the audio CD, and a proper way to reduce the word length from 16bit to 1bit, which will be the basis of a PDM system.Most modern digital audio systems use multi-bit PCM (pulse-code

scene of the accident. If a serious accident occurs in the tunnel, a fire may occur, therefore, after an accident occurs in the tunnel, an emergency evacuation broadcast system is urgently needed. FMFM broadcast in the tunnel is a good emergency broadcast. Drivers can obtain evacuation and emergency command information through the radio, this service provides emergency incident command and handling to guide drivers to avoid risks. Therefore, whether in terms of security or service to the work a

What is a frequency converter. The frequency converter is the power control device which transforms the power frequency supply into another frequency by using the switching function of the electric semiconductor device. The frequency converter is the power control device which transforms the power frequency supply into another frequency by using the switching function of the electric semiconductor device. Can be divided into AC-ac frequency converter, ac-Straight-AC frequency converter. AC-Fre

-purpose system and the dynamic range of the useful signal change greatly. In the case of more than 50dB and different ambient power differences, it is not enough to achieve 1mb/s above rate, only by encoding and processing gain. Conversely, it is easier to avoid interference because the signal can be sent when the frequency (or time) is not disturbed (or when the interference is low). If the time-avoiding interference method is used, the signal sent will be aborted when the pulse interference i

measure the frequency of F2. Reproducibility = (f2-f1)/F2.Frequency Voltage Control Range: Adjust the frequency control voltage from the reference voltage to the specified end voltage,Crystal OscillatorThe minimum peak value of the frequency.Note: The reference voltage is + 2.5 V, and the specified end voltage is + 4.5 V and + 2ppm v. When the Voltage Controlled Crystal Oscillator controls the voltage at + V frequency, the frequency changes, when the frequency change is + 1ppm when the voltage

Automatic scanning read/write distance 4 W transmitting antenna unidirectional ≥ 1.3 m, omnidirectional ≥ 0.9m antenna connector 50Ω SMA Communication Interface RS/232, VGA, DI power warning light, DC12V; Control System and LCD, DC24V, 1A warning light source over-Bright Light Emitting Diode Communication Interface RS232, VGA, USB, RJ45, DI, DO power supply 220 V, AC single board control module operating system Windows, Dos transmit power ~ 10 W 1 dB operating frequency 13.56MHz7kHz antenna int

arrive at the scene of the accident. If a serious accident occurs in the tunnel, a fire may occur, therefore, after an accident occurs in the tunnel, an emergency evacuation broadcast system is urgently needed. FMFM broadcast in the tunnel is a good emergency broadcast. Drivers can obtain evacuation and emergency command information through the radio, this service provides emergency incident command and handling to guide drivers to avoid risks. Therefore, whether in terms of security or service

management personnel to arrive at the scene of the accident. If a serious accident occurs in the tunnel, a fire may occur, therefore, after an accident occurs in the tunnel, an emergency evacuation broadcast system is urgently needed. FMFM broadcast in the expressway tunnel is a good emergency broadcast. Drivers can obtain evacuation and emergency command information through the radio, this service provides emergency incident command and handling to guide drivers to avoid risks. Therefore, whet

tunnel management personnel to arrive at the scene of the accident. If a serious accident occurs in the tunnel, a fire may occur, therefore, after an accident occurs in the tunnel, an emergency evacuation broadcast system is urgently needed. FMFM broadcast in the expressway tunnel is a good emergency broadcast. Drivers can obtain evacuation and emergency command information through the radio, this service provides emergency incident command and handling to guide drivers to avoid risks. Therefor

According to different signal transmission and receiving methods, ISO/IEC14443-3 defines two types of cards: typea and typeB. Their differences mainly lie in the modulation depth of the carrier and the encoding method of the binary number. When transmitting signals from a read/write machine to a card, the two transmit signals through the RF carrier of 13.56mhz. Typea represented by Philips and Siemens. It sends the miller code with 100% ASK

. Figure 1 shows the principle of a visible-light Wireless Communication System Based on USB interfaces. The system consists of three parts: 1. the interface circuit connects the computer and optical transceiver, converts the USB signal from the computer into a signal suitable for transmitting circuit modulation, and converts the signal sent from the receiving circuit into a USB signal to the computer, implement high-speed wireless duplex communicatio