qpsk modulation

existing communication technologies from a relatively high level and system perspective, and analyzed many seemingly completely unrelated technologies in a unified mathematical expression, in particular, the popular technologies such as MIMO, Opportunistic Communication, OFDM, and multi-user Communication have been interpreted from the viewpoint of information theory, this is helpful for us to grasp the current development direction of wireless communication at a higher level. We strongly recom

Reprinted: http://blog.chinaunix.net/uid-22028680-id-3208043.html 1. The channel is locked by the input frequency, symbol rate, and modulation method.2. Receive the Pat table on the current channel. If it is known that the PID of Pat is fixed to 0, the Pat table will be parsed and saved.3. Obtain the NIT table pid from pat:If program_number is 0, network_pid is obtained. Of course, the NIT table PID is fixed as 0x0010 is also a solution, but this sol

V. Modem Glossary 　　 At command (atcommands): a modem command language invented by Hayes, which is now a de facto standard and used by all modem manufacturers. The name of each command starts with the letter ". At is followed by letters and numbers to indicate specific functions. For example, "atdt" is a dialing command, other Commands include "initialize the modem", "control the speaker volume", "specify the number of calls for the modem to initiate a response", and "select the error correctio

construction include class style, functional requirements for value-based Student Management, class honors, student works, student centers, etc. Xinyi aojiashi Electronics Co., Ltd. was established in 2012. It specializes in the production of Cable Digital TV front-end products and undertakes cable TV iptv system smart interactive TV solution design and digital TV transformation project.I. okasi digital TV front-end products include the following four categories:1. Analog Front-end: modulated d

Mbps or above, and the downlink speed is higher. Cable modem is a dedicated MODEM that integrates MODEM functions, bridging encryption and decryption functions, Nic and Ethernet Hub functions. It does not require dial-up access, does not occupy telephone lines, and can be connected permanently. Data signals are transmitted to users' homes through fiber-optic coaxial hybrid network (HFCs). cable modem completes signal decoding, demodulation, and other functions, and transmits digital signals to

network data through FM radio frequency modulation signals at idle time. "It can monitor network conditions, and choose to transmit data with FM during idle hours to bypass other people's network lines to avoid Back-Off," said Marcel Flores, a doctoral researcher ." The team transmits wireless network signals through commercial FM radio frequency modulation signals. The frequency ranges from 87.5Mhz ~ Betw

Wireless Internet access can be achieved in a variety of ways, such as surfing on the wireless network. Next, we will give a brief introduction to EDGE wireless Internet access, and make a rough comparison with the appropriate user groups based on the characteristics of each method. Hope to help you. What is EDGE? EDGE is short for Enhanced Data Rate for GSM Evolution, that is, Enhanced Data Rate GSM Evolution technology. EDGE is a transitional technology from GSM to 3G. It mainly uses a new

meet different coverage environments and planning requirements, you can flexibly choose wireless resource blocks and modulation encoding methods used by users. In the actual network, the number of wireless resource blocks, user rate, modulation and encoding methods, and signal-to-noise ratio of the business are mutually affected, resulting in complicated 4G network scheduling algorithms, during the plannin

modulation, multiple access technology and receiver fields. In the field of coding and modulation, we will focus on Nonlinear Multi-user pre-encoding, new combined modulation coding, network coding and other technologies. In the field of multi-access technology, we focus on non-orthogonal multi-access technology. In the receiver field, the key research can suppo

wide instantaneous bandwidth while ensuring efficient mirror-frequency rejection and minimizing lo leakage. Mirror frequency rejection and lo leakage performance can be achieved with wideband quadrature correction, the receiver path is optimized and can be used as a vector signal analyzer for wideband demodulationLow if mode and in-band re-adjustmentThe low if receiver is another type of receiver using the IQ demodulator with the same block diagram as the 0 if receiver shown in Figure 5. In a 0

Deep Learning Study Notes:Deep Learning 21: Depth learning attempt for modulation signal classification 3Deep learning 20: Depth learning attempt for modulation signal classification 2_CNNDeep learning 19_ Depth Learning UFLDL Tutorial: convolutional neural network_exercise (Stanford University Deep Learning tutorial)Deep learning 18:DBM's study and practice _ reading paper "Deep Boltzmann Machines" notesDe

Forum post Serial-The principle of communication is relatively good technology paste, address http://bbs.c114.net/forum.php?mod=viewthreadtid=394879page=0Excerpt a few of the more rewarding parts.1 The author proves that convolution actually represents the coefficients after the multiplication of two polynomial, if the signal can be expressed in the form of a polynomial, then the multiplication of the signal can actually be expressed as the coefficient convolution of the polynomial. Can you do t

The training and 2015 National Electronic Design competition is over.Many things were learned during the training period.Just started to use 2sc3355 to do 1.4GHz RF amplifier, using Microstrip line to do transmission line, on the Vector Network Analyzer to observe the parameters such as S11,S12,S21,S22. The amplifier effect is not very good. This and the circuit layout and general capacitance inductance in the high-frequency characteristics of the changes have a great relationship.Next, the FM t

the configurations has similar responses to input levels, and that the 2N3904 Have a bit less offset, as you would expect Fromfigure 2. The output can drive a signal level meter or following electronics as part of an Automatic-level-control or Automatic-gain -control Loop. the transfer function Infigure 1also shows a sudden increase in inverted current at app Roximately 7.6V, which occurs at the reverse breakdown voltage for the emitter-to-base junction. Because you know in the "the" the base i

: frame, ether frame, Ethernet frame Network layer: IP datagram Transport Layer: TCP segment, TCP message segment Unidirectional communication (simplex) [can only be sent], bi-directional alternating communication (half-duplex communication) [cannot simultaneously receive \ Send], two-way simultaneous communication (full-duplex communication) [may simultaneously receive, send] Baseband signal: Data signals such as text and images are baseband signals Band-Pass signa

standard bluetooth technology uses 79 data channels ). Another reason for requiring the Bluetooth Low-energy technology to enable wireless connection for the shortest time is that it has 1 Mbps of original data bandwidth-a larger bandwidth allows more information to be sent in a shorter period of time. For example, another wireless technology with kbps bandwidth needs to be enabled eight times (consuming more battery energy) to send the same information ). Bluetooth Low-energy technology "Compl

); % calculates the new coordinates generated by the Gabor function rotationX=tpx*cos (theta) +tpy*sin (theta);Y=-tpx*sin (theta) +tpy*cos (theta); % calculation Gauss functionz=1/(2*pi*sigmax*sigmay) *exp ( -0.5* (X/sigmax). ^2+ (Y/sigmay). ^2)); % calculated modulation factorExptab=exp (-j2*pi* (TPX*MU+TPY*MV)/n); %gauss function modulated by modulation factorHp=z.*exptab; % matrix transpose to generate X

I. The concept of PWM and duty-free ratio ①PWM: Also known as pulse width modulation technology, is an analog control mode, the PWM waveform as shown below. ② duty cycle: refers to the proportion of the high level in a period. For example, a duty cycle of 50% means that the high level accounts for half of the period. Two, PWM fixed frequency speed regulation principle In the PWM speed regulation system, it is generally possible to change the dut

receiver can be from all other signals from the background to restore the original information code (this process is called the extension). CDMA can be divided into direct sequence spread spectrum (DS), FH (FH) and Hop Time (TH) According to the modulation method of obtaining bandwidth signal, as shown in Figure 2 below: 2 Rake Receiver Rake receiver is also known as Multipath receiver, that is, mobile Taichung has multiple rake receivers, because

junction unit, ceramic head connection should ensure that each connection point attenuation is not less than 0.4dB. The connector of the plastic head has a attenuation of less than 0.5dB for each connection point. Integrated wiring system should adopt optical fiber diameter 62.5μm fiber cladding diameter 125μm of slow-change enhanced multimode fiber optic cable, nominal wavelength of 850nm or 1300nm, also can use nominal wavelength of 1310nm or 1550nm single-mode optical cable. The digital se