dqpsk modulation

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

FHSS or DSSS 2 Mbps 802.11a 5 GHz OFDM 54 Mbps 802.11b 2.4 GHz HR-DSSS 11 Mbps 802.11 GB 2.4 GHz OFDM 54 Mbps 802.11n 2.4 or 5 GHz OFDM 540 Mbps theoretical value) Wireless Network Protocol 1. Traditional 802.11 1997 release Two Original data rates: 1 Mbps and 2 Mbps Frequency Hopping FHSS) or direct sequence frequency spreading DSSS) The three 2.

the data transmission rate. The main function of MAC-hs added to NodeB is to schedule sent data and control retransmission of data. Retransmission is directly controlled by NodeB, which avoids the delay from RNC to UE, increases the retransmission rate, and reduces the latency during data transmission. At the same time, NodeB can quickly schedule the size of data to be sent and objects to improve the cell throughput. Because the shared channel uses the system to adaptive adjust the User

Wireless network technology is becoming more and more powerful. to master the RF communication technology, we will give you a detailed description of the wireless technology, suppliers are attempting to use "easy to install", "seamless connection" and other commitments to mask abnormal Wi-Fi physical layer signals. However, you need to use RF technology to manage a large wireless network, just as you must know that if the connection is used to build an effective lan. Knowledge of RF communicatio

coupling between the reader and the electronic tag:(Ⅰ) inductance coupling. The transformer model, through the space high frequency alternating magnetic field realizes the coupling, is based on the electromagnetic induction law.(Ⅱ) Electromagnetic backscatter coupling. The radar principle model, the emitted electromagnetic wave, touches the target to reflect, simultaneously carries back the target information, is based on the electromagnetic wave space propagation law. Induc

status is similar to the AIFF in the Macintosh computer. This format is 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 pu

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

At present, China's broadband access network has developed very mature and many new technologies have emerged. Here we introduce the development status of VDSL and analyze some of its problems, I would like to share it with you here and hope it will be useful to you. 1. Technical Standards of VDSL VDSL currently has two major incompatible technical standards: one is DMT discrete multi-audio modulation, and the other is CAP and QAM without carrier ampl

The goal of network development is to achieve better performance, wider bandwidth, and lower costs. I am wondering if I want to introduce a broadband wireless access technology and orthogonal frequency division multiplexing (OFDM). The birth of this technology will bring new prospects for the future wireless access technology. One of the main requirements of the next-generation Broadband Wireless Access System (BWA) is to operate and maintain efficient performance under the conditions of OLOS or

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