ofdm modulation

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

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,

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

is very high. When the oscillator is used, a very stable oscillation can be generated for the filter, you can obtain a very stable and steep band-pass or band-resistance curve. Crystal Oscillator-Main Parameters Parameters Basic description Frequency Accuracy When the nominal power supply voltage, nominal load impedance, reference temperature (252 ℃), and other conditions remain unchanged, the frequency of the crystal oscillator is equal to the maximum allowable deviat

of encoder extracts a set of parameters, which are sent to the receiver to export the speech to generate a pattern. Audio quality is not good enough. The hybrid encoder integrates the strengths of the waveform encoder and sound generator. Waveform encoder 2.1 Waveform encoder design is often independent of the signal. Therefore, it is applicable to the encoding of various signals, not limited to speech. 1. Time Domain Encoding A) PCM: pulse code modu