qam modulation

power and average power in the entire burst range at low, medium, and high frequency points. The specifications require that the peak power and average power be smaller than 23dbm and 20dbm respectively and meetThe following requirements: If the EUT power level is 1, the average power>0 dBm; if the power level of EUT is 2,-6dbm (2) power density The initial state is the same as (1). the tester finds the highest-power frequency point within the MHz band by scanning the frequency point, and then

HSPA is a new feature introduced by WCDMA R5. It uses high-order modulation of 16QAM and multi-Code Time Division Technology, greatly improving the packet transmission rate. High-order modulation: Higher-Order modulation can make transmission more efficient, but higher-order modulation also requires greater power and h

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

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

In the wireless data transmission system, the wireless transceiver chip is the core carrier of the technology. As the signal sending and receiving, modulation, and debugging, it plays an absolute core role. We will compare and analyze several Wireless Transceiver Chip Solutions. 1) CC1000 Wireless Transceiver Chip Solution CC1000 is a single-chip programmable RF transceiver chip launched by Chipcon. Based on Chipcon's Smart RF technology, CC1000 can w

basic waveform representing different discrete values (1 yards can carry n bits of information)Channel: The media that transmits information in one Direction (daily communication lines are: 1 channels to send messages + 1 channels to receive information)Unidirectional communication (simplex): Communication in One Direction with no reciprocal directionBidirectional alternating communication (half-duplex communication): Both sides of the communication can send and receive information, but cannot

The radio has been in use for a long time, and for a long time it was born a group called the Ham Tribe (^_^ cq), the man who ate ham all day. Radio and the Internet: There are also some security risks, such as: in the transmission of wireless signal does not take into account the CRC check, encryption and other security issues.Small scenario: If you use the Wireless key card to unlock the car on one day and press the second time to unlock it, then your car has been targeted by hackers!A new att

linear pulse code modulated by the digital signal. So the decimation filter is actually the equivalent of a code-based converter. Because the ∑– modulator has a very high sampling rate, it is usually higher than the Nyquist sampling frequencyMany times, so the ∑– modulator is also known as Oversampling ADC Converter. This type of ADC uses a very low quantizer, which avoids the difficulty of making high-level converters and high-precision resistor networks, and because it uses ∑–

quantification of a surface point, the following operations are performed :. Most BRDF can satisfy this attribute to a certain extent, which makes rendering results look more natural. However, it is not easy to strictly satisfy this constraint, it requires that the energy cannot be lost or reduced from the ground (these may be important in physical rendering ). Anisotropy isotropy, : If BRDF is about a surface normal vector that is rotated symmetric, its result only depends on and the differe

one of the applications of the resource Exchange file format (RIFF), which typically stores audio assets encoded with pulse encoding in chunks. It is also one of the most commonly used specifications in music enthusiasts. Because this audio format is not compressed, there is no distortion in sound quality, but the volume of the archive is larger in many audio formats. "We can see the above mentioned two keywords RIFF and pulse code modulation. So let

of modulation is generally fixed deformation adjustment, fixed-color modulation, setting color modulation and so on. 1, fixed deformation adjustment The essence is to maintain the form (pattern, flower shape, style, etc.) unchanged under the premise, only to change the color and to achieve the purpose of changing the tone, is the textile, clothing, decoration,

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