ofdm modem

signal-to-noise ratio. What is OFDM?Orthogonal Fre-quency Division MultiplexingThe basic principle of OFDM is orthogonal frequency division multiplexing. This technology is the basis of the HPA Alliance HomePlug Powerline Alliance) industrial specifications. It uses a nonconsecutive multi-Tone Technology that combines large numbers of signals called carriers in different frequencies into a single signal, t

Alliance (homeplug Powerline Alliance). It uses a non-consecutive multi-Tone Technology, combines a large number of signals in different frequencies called carriers into a single signal to complete signal transmission. Because this technology can transmit signals under clutter interference, it is often used in transmission media that is vulnerable to external interference or poor resistance to external interference. In fact, OFDM is not a new technol

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

let people understand, is probably the distinction between a layer and two levels of the watershed. To make a cock-and-thread analogy: The first layer is the cultivation of the people, even if the "will", but also has built a base, elixir, dollar and other realms of the points, and the entrance examination is the days of robbery, not to the Mahayana state, eventually to become a robber, the second layer is heaven, also has its own fairy, Jinxian of the points, and can be repaired to the Tao I a

base, elixir, dollar and other realms of the points, and the entrance examination is the days of robbery, not to the Mahayana state, eventually to become a robber, the second layer is heaven, also has its own fairy, Jinxian of the points, and can be repaired to the Tao I always feel that I am a professional is a "little fairy", but it is "small white" hit the face.This is a big negative impact on me, one is the suspicion of their own technology home for a long time, the ability to express serio

References: Principles and Applications of OFDM mobile communication I. Concepts of inter-symbol interference (ISI) and inter-channel interference (ICI) Ii. reduced protection interval (ISI) 3. reduce ICI by the cyclic prefix Iv. Block Diagram of the OFDM system after protection interval and cyclic prefix are added 5. Select the protection interval method ==================================== ===== The conce

Study on the Influence of optical fiber nonlinear effects on optical OFDM signals (1) Optical Orthogonal Frequency Di-vision Multiplexing (O-OFDM) is a new type of Optical transmission technology that has been developed in recent years, it applies Orthogonal Fre-quency Division Multiplexing (OFDM) technology to optical fiber channels. Transmitting

Spectrum utilization, supporting high speed multimedia services, system capacity, multipath channel interference and other factors are the main starting points for the majority of fixed broadband wireless access devices to select CDMA (Code Division multiplex) or OFDM (Orthogonal Frequency Division multiplexing) as the key technology for point to Point (PMP). And these two technologies have their own strengths in these areas, so the equipment business

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 efficien

Instead of CDMA, OFDM technology has become the core technology trend of the next generation of wireless communication because of its advantages. The replacement of CDMA technology by OFDM technology has become the trend of the next-generation wireless communication technology because it has the following five advantages: High spectrum efficiency Due to the FFT processing, each sub-carrier can partially ove

The principle of OFDM signal transmitter is that user signals are input in serial mode, and the rate is r codeword/second. These codes are first sent to a serial-parallel converter, so that the serial input signal is output to M lines in parallel. The data transmission rate on any one of the M lines is R/M codeword/second. The OFDM code is subsequently sent to a fast Fourier inverse transformation module f

The combination of MIMO and OFDM technologies is considered as the core technology of the next generation high-speed wireless LAN. This paper comprehensively analyzes the application of MIMO and OFDM technology in Wireless LAN, discusses the key technologies of MIMO and OFDM, and looks forward to its development prospects. 1. Introduction As a new communication

Analysis on the reason of frequent drop of modem 1, if the ADSL modem just as bridging mode access, first through the ADSL Modem Web page to view the line attenuation, Snr margin (this value is normally 15-40db, if less than 10db, indicating that the current line quality is not good enough), line speed and other parameters, If these parameters are abnormal, plea

What does the ADSL modem mean? often have netizens to consult this problem, ADSL modem is a modem, commonly known as "cat", users of ADSL broadband after (telephone line internet), must use ADSL modem this equipment, can normal internet. 　　Why do you use ADSL Modem? 　　ADS

Schmidl Algorithm CodeAlgorithm principleTraining sequence Structure T=[a A], where a is a representation of a complex pseudo random sequence PN, a sequence of symbols obtained by N/2 point Ifft transformation\[m (d) =\frac{\left | P (d) \right |} {r^{2} (d)}^{2}\]\[p (d) =\sum_{m=0}^{l-1}r^{*} (d+m) r (d+m+l) \]\[r (d) =\sum_{m=0}^{l-1}\left | R (d+m+l) \right |^{2}\]\[l=n/2\]The obtained D corresponds to the starting position of the training sequence (which does not contain a loop prefix).The

SerialPort enables modem incoming call display A friend took a case, but had to go on a business trip temporarily, so I called some functions for me to do it. I have always paid attention to WEB programming, but I am still unfamiliar with serial programming.ArticleA lot. Of course, it is better to count the articles in cnblogs for help. Write this into your blog for future reference, hoping to help those who need help.This section mainly describes ho

The LTE network has several key technologies, namely: Ofdm,amc,harq,mimo,icic,sonToday first to understand OFDM; (orthogonal Frequency Division multiplexing) Orthogonal frequency Division MultiplexingThe channel is divided into multiple orthogonal sub-channels, the high-speed data signal is converted into parallel low-speed sub-data stream, and modulated to each sub-channel for transmission.Orthogonal Frequ

Operating environment: FreeBSD 3.4-release, the same dimension 56K external modem First, set/etc/ppp/ppp.conf #vi/etc/ppp/ppp.conf If the modem company COM1 Port is set to: Default Set DEVICE/DEV/CUAA0 (other can be invariant) ..... If the modem company COM2 Port is set to: Default Set DEVICE/DEV/CUAA1 (other can be invariant) ..... Second, run PPP int

"Note one: Single-carrier and Multicarrier transmission"MIMO-OFDM technology is the key technology of 3g-lte,wimax communication system and WLAN such as ieee802.11a,ieee802.11n and so on, as a communication dog, these should be knowledge that must be mastered. However, the undergraduate communication course is boring and disconnected from the actual system, in class, the teacher always lists a lot of professional terminology, what is said, but the con

example, P1;P2 indicates that P1 is executed first and then P2 The previous command executes successfully before the next command is resumed. Example: P1 p2, if P1 execution succeeds, the P2 is executed, otherwise, p2 is not executed; || The previous command failed to continue execution of the next command. Example: P1 | | P2, if P1 execution succeeds, do not execute P2, vice versa, only execute P2; ! Commands in the execution history