qpsk modulation

backplane capacity exceeding 1Gbps. CMTS allows cable operators to establish high-density and highly adjustable termination systems for their data-over-cable (DoC) services. The core module of CMTS is cable Access Router, which provides routing connections from the Internet or from the internal backbone data network to the RF (CATV) network. By working in conjunction with the QAM modulator (downlink module), if output can be provided in a 6MHz and MCNS compatible cable data channel. Dual Mode (

The English quadraturephaseshiftkeying abbreviation, stands for orthogonal phase shift keying, is a digital modulation method. The four-phase Phase Shift Keying Signal is short for "PSK ". It can be divided into absolute phase shifting and relative phase shifting. The following figure shows the principle of the following: The following digital demodulation methods are available: analog-to-digital conversion, extraction or interpolation, matching fil

generation of GSM, TDMA is a multiple access way, Gmsk for modulation, duplex mode is based on FDD TDD, the core network of CS domain as the main mobile communication system, and GSM "evolution", the so-called WCDMA, CDMA is a multiple access mode, QPSK for modulation, The duplex mode is FDD, the core network has the CS domain on the basis of the introduction of

of continuous improvement. A large number of active and passive devices are available, reducing costs quickly. The power flat, non-linearity, color dispersion, and polarization mode dispersion performance of various devices are significantly improved, so that the power redundancy requirements of the system design can be moderately relaxed. In particular, DQPSK/DP-QPSK modulation technology, Electronic Disp

In electronic circuits, power supply, amplification, oscillation, and Modulation circuits are called Analog Electronic Circuits because they process and process continuously changing analog signals. 1. Feedback Feedback refers to sending output changes to the input end in some way as part of the input. If the return part and the original input part are subtracted, It is negative feedback. 2. Coupling An amplifier usually has several levels, and the as

The main technical specifications of WCDMA are: support high-speed data transmission (384kb/s when moving slowly, 2mb/s when walking indoors), asynchronous BS, support variable speed transmission, frame length 10ms, chip rate 3.84mb/s. The main features are as follows: Base Station synchronization mode: support asynchronous and synchronous base station operation mode, network convenient, flexible; Modulation mode: The behavior BPSK, the next behavio

use of channel bandwidth, but also avoid using high-speed balancing and anti-Burst Noise errors. OFDM is a special multi-carrier communication solution. The information flow of a single user is serialized/transformed into multiple low-rate bitstreams, and each bitstream is sent using one subcarrier. OFDM does not use a band-pass filter to separate subcarriers, but uses the fast Fourier transform FFT) to select waveforms that can maintain orthogonal even if they are overlapped. OFDM is a high-sp

user is serialized/transformed into multiple low-rate bitstreams, and each bitstream is sent using one subcarrier. OFDM does not use a band-pass filter to separate subcarriers, but uses the Fast Fourier Transform (FFT) to select waveforms that can maintain orthogonal even if they are overlapped. OFDM is a high-speed transmission technology in wireless environments. The frequency response curves of wireless channels are mostly non-flat, and the main idea of OFDM technology is to divide a given c

converter, it determines that it must occupy a certain amount of space and consume a certain amount of power in the system. Therefore, in system solutions that require convenient portability, the static D/A converter has to be replaced with [1].So people choose the so-called "Digital basis" D/A converter. There are two methods for digital D/A conversion: PWM (P Ulse Width Modulation) Pulse Width Modulation

Abstract: As more and more wireless devices enter people's lives, a large number of multimedia services also emerge. As multimedia transmission services require a certain amount of bandwidth, the bandwidth of traditional wireless networks also shows some shortcomings in expanding multimedia services. The emergence of OFDM modulation technology solves the bandwidth requirements of users to a certain extent. In addition, the OFDM

Transferred from: http://baike.baidu.com/link?url= KEOJCOEXYDZUH8N7BNUGEDUTAGLDGDI7ESJUSZESPUREBK0NI6SFMTPWGIRED-H-L3ZZ7CY6QSHXVHHILK7BCQ the speed at which a microcontroller or computer communicates at the serial port. Refers to the signal is modulated after the change in the unit time, that is, the number of times the carrier parameter changes in the unit time, such as 240 characters per second, and each character format contains 10 bits (a starting bit, 1 stop bit, 8 data bits), the baud rate

able to achieve my purpose before I put the Linetype parameter in ' color ', i.e.Plot (x, y, ' o ', ' color ', [0 1 0]);This will find that your MATLAB can achieve a variety of colors!Below ~ Draw a disc on the opposite side.QPSKCONSTELLATIONNBSP;=NBSP;[-1+1INBSP;1+1I;NBSP;-1-1INBSP;1-1I]/SQRT (2); Qpsk=reshape ( Qpskconstellation,1,[]); num=40;outter=60;fornn=1:o utterqpsk=qpsk* (outter-1)/outter;c=rand (

Figure 8-4-3 of the voltage controlled oscillator, this characteristic describes the oscillation frequency ω U of the voltage controlled oscillator. Take ω 0 Center, UC with input signal voltage (T) changes. The expression for this feature is (8-4-6) When UC (T) The oscillation frequency ω U of the voltage controlled oscillator varies with time It also changes with time. The phase-locked loop enters the "Frequency traction" and automatically tracks and captures the frequency of the input signa

This article mainly discusses the technical advantages of the wireless LAN Standard IEEE802.11g. Data Transmission Based on OFDM technology With the wide application of wireless LAN technology, users have higher and higher requirements on data transmission rates. However, in the indoor environment, the complex electromagnetic environment, the multi-pass effect, frequency selective fading, and other interference sources make it more difficult to achieve high-speed data transmission in wireless c

there are tags nearby. RFID is usually called a near-pairing system for communication at a very close distance. The range of near-pairing systems is usually 0 to 1 cm. This means that the tag is appended to the reader or pressed to the reader. The advantage of this close distance is that the label battery plant can produce a lot of energy. This energy is sufficient to support tag communication without the need for Built-in power. Near-matching is also conducive to highly confidential occasions.

------------------------------------------------------------------------------- Chorus reverbParameter value range descriptionMod. freq0.8hz0.1-20Hz Modulation SpeedMod. depth40 % 0-100% modulation depthMod. dly1.3ms0-24ms delay time before initiation of modulationRev. time2.4s0.3-30s reverb timeHigh ratio0.70.1-1 high-frequency attenuation rateDiffusion70-10 reverb DiffusionDelay Time between ini. dly30ms

the data is represented by binary or more discrete level values. Therefore, the communication channel maximum transmission rate and channel bandwidth have a clear relationship, so people can use "bandwidth" to replace the "rate." For example, people often use the network's "high data rate" to express the "high bandwidth" of the network. So "bandwidth" and "rate" are almost synonymous in the discussion of network technology. ------------------------------------------------------ bit rate. Baud

attenuation rateDiffusion60-10 reverb DiffusionThe delay time between INI. dly12.0ms0.1-200.0ms and early reflection.Cut-off frequency of lpf4.0khz1.0khz-16108khz.thru low-pass filterCut-off frequency of hpfthruthru, 32hz-8khz high-pass filter Reverb vocal used for voice and chorus reverbParameter value range descriptionRev. time1.9s0.3-30.0s reverb timeHigh ratio0.50.1-1.0 high-frequency attenuation rateDiffusion60-10 reverb DiffusionDelay Time between INI. dly16ms0.1-200.0ms direct and earl

amplifier. This product is specially designed to support GSM/edge pam and 3G/3.5g pa. Because the space of the circuit board in the mobile phone is very precious, the designer no longer needs to use two independent step-down converters. FAN5904 supports 3G wireless standards from WCDMA to HSUPA +, as well as the world's popular CDMA 200 1x EV-DO. In addition, the device supports China's 3G standard TD-SCDMA and HSUPA for TD-SCDMA signal modulation fo

. When the upper type is not equal to zero, the phase of the PLL is not locked, and the frequency of the input signal and the output signal are different, and U C (t) changes with time. As shown in Fig. 8-4-3, the voltage-controlled oscillator is characterized by the oscillation frequency of the voltage-controlled oscillator ωu is centered on the ω0 and varies with the input signal voltage u C (t). The expression for this attribute is (8-4-6) that when u C (t) changes with time, the oscillation