dqpsk modulation

. Baud rate Index according to the signal to the carrier modulation rate, it is in the unit time the carrier modulation state changes the number of times to express, its unit is Porter (Baud). The baud rate is related to the bit rate: bit rate = baud rate x the number of bits corresponding to the individual modulation state. Obviously, the bit rate of the two-ph

, connect to other trunk optical fiber cables, lan, and local computer networks, and exchange data through the front-end devices of CMTS (Cable Modem Termination System) Cable, enables interactive dual-item data transmission.3 The Cable Modem transmission standard and frequency CM are modulated by 64QAM or 256QAM (orthogonal Amplitude Modulation) in the middle and lower lines of the hybrid network transmission of the fiber optic Cable ); the signal to

. Baud rate Index according to the signal to the carrier modulation rate, it is in the unit time the carrier modulation state changes the number of times to express, its unit is Porter (Baud). The baud rate is related to the bit rate: bit rate = baud rate x the number of bits corresponding to the individual modulation state. Obviously, the bit rate of the two-ph

synchronized.2SupplementEditBit rate in the digital channel, the bitrate is the transmission rate of the digital signal, which is represented by the number of effective bits (bits) of the binary Code transmitted within a unit of time, expressed in units of bit/s (bps) per second, kilobits per second (Kbps), or megabits per second (Mbps) ( Here K and M are 1000 and 1000000 respectively, instead of 1024 and 1048576 when the computer memory capacity is involved. Baud rate baud rate index according

more open frequency policies and resources, packet microwave product transmission capacity has greatly exceeded the previous generation of TDM microwave products. At present, the most advanced microwave products modulation and demodulation mode has been able to support up to 2048QAM, compared with the traditional TDM microwave maximum 256QAM modulation mode, the spectrum utilization efficiency increased by

There is types of frame structure in the LTE standard, type 1 and type 2. Type 1 uses Frequency Division duplexing (Uplink and downlink separated by Frequency), and TDD uses time division Duplexin G (Uplink and downlink separated in time). This overview covers both LTE FDD Type 1 signals and LTE TDD type 2 signals described in the standard documents listed in The About Opts BHD and bhe:lte modulation analysis topic. This overview isn't a exhaustive de

systems that can be upgraded from cdmaone to smooth. The route of its evolution is Cdmaone--cdma20001x--cdma20001xev. Another mainstream of the third generation of communication technology is the second generation of GSM standard developed by the WCDMA technology, because GSM uses TDMA (time division Multiple Access) modulation mode, and WCDMA uses CDMA (Code Division Multiple Access) modulation, its air c

Hue Change and type The change of tone, namely tonal conversion, is an important subject in the design of color selection in art design, with many kinds of varieties and designs, and the form of modulation is generally fixed deformation adjustment, fixed-color modulation, setting color modulation and so on. 1, fixed deformation adjustment The essence is to mai

digital signal into an analog signal, and the receiver uses the demodulator to convert the received analog signal into a digital signal, which is the modulation and demodulation of the signal.The device that implements the modulation and demodulation tasks is called a modem. When using the frequency band transmission, each side of the communication is connected to a modem, and the digital signal is sent to

transmission rate is equal to twice times of the bandwidth to ensure the non-interference between the front and rear code elements. Rmax (maximum information transfer rate) = B*2 B: Bandwidth B. Noise (bandwidth and signal-to-noise ratio) Calculate with Shannon formula C: (channel capacity) channel error-free maximum information transfer rate, that is, rmax (information transfer rate maximum) B: Bandwidth S/N: Signal-to-noise ratio (db) The most common is the signal to noise ratio 30db, can g

The G optical transmission technology based on digital coherent receiving PM-QPSK modulation has a milestone in the long-distance optical transmission technology history. The error correction coding technology can be used to further improve the system performance when modulation, detection, balancing, and multiplexing cannot meet the system transmission performance requirements. To achieve the current trans

sending end. It is typical, for example, a modulation; however, many PCs now use built-in modem. Receiver: receives a signal from the transmission system and converts it to the information processed by the target device. A typical device is a modem. The analog signal from the transmission line is demodulated to extract information, restores the digital bit stream generated by the sender. End point: the end device obtains the sent digital bit stream f

time, and the other device can receive the data. However, the communication parties send and receive messages in turn in accordance with certain communication protocols.3. Full Duplex ModeBoth parties are allowed to send and receive messages at the same time. In this case, device A can receive messages at the same time as Device B. The full duplex mode is equivalent to combining two tickets in the opposite direction. Therefore, it requires two data transmission lines. In computer serial communi

addition, compared with the wireless cellular network of mobile communication, this fixed wireless network shows its superiority in terms of data transmission speed, access reliability, and spectrum usage efficiency. Generally, FWA is designed based on line-of-sight transmission LOS, that is, the radio wave transmission between each user and the Access Point BTS is based on line-of-sight transmission LOS. Each user is equipped with a precisely oriented, narrow, and fine-beam antenna with a high

. The most common Ethernet standard in a data center is 1000Base-T or 1000Base-TX, some data centers have started to adopt 10G Base-T. Therefore, this article will mainly study the relationship between these three standards and off-line crosstalk. This article will begin with the three standard modulation methods, analyze their ultimate signal-to-noise ratio, and then compare the signal-to-noise ratio that can be achieved by the transmission media, fi

HSDPA is a high speed downlink packet access, it is 3GPP in the R5 protocol in order to meet the demand of the upper/lower data business is a modulation and demodulation algorithm, which can not change the already built WCDMA network structure, the downlink data service rate to 10Mbps. This technology is an important technology to improve the downlink capacity and data service rate in the later stage of WCDMA network construction. The application of H

speed of static difference slightly larger. (3) Limited unipolar mode, in addition to the unipolar modulation, the energy-saving braking path is limited. Advantages: The control circuit is simple, if connected to the H-bridge mode, can also turn positive and negative. Disadvantages: Can not brake, not energy braking, the load exceeds the set speed can not provide reverse torque. Speed adjustment static difference is big, the speed performance is ve

HSDPA refers to high-speed downlink grouping access. It is a modulation and demodulation algorithm proposed by 3GPP In R5 Protocol to meet the asymmetry of upstream/downstream data services, it can increase the downstream data service rate to 10 Mbps without changing the structure of the constructed WCDMA network. This technology is an important technology for improving downstream capacity and data service rate in the later stage of WCDMA network cons

become a problem to be solved in the communication field. Cognitive Radio (CR) is an intelligent spectrum sharing technology. It can effectively improve the utilization of spectrum resources by making secondary use of the authorized spectrum. It has become a hot topic in the communication field. In the 802.11 Wireless LAN [1], 802.16 MAN [2] and 3G mobile communication networks [3], Cognitive Radio technology has been applied to increase the system capacity, and began to study the application o

In the previous article, we introduced the principle of the HART protocol of SYM20C15. Here we will mainly explain the working process of SYM20C15. We know that the HART protocol is a communication protocol with modulation and demodulation characteristics. Then we will divide it into the modulation part and the demodulation part to analyze the two. SYM20C15 Workflow SYM20C15 is a low-power modem designed to