ofdm wifi

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

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

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

This article mainly gives you a detailed description of the OFDM technology on the vro and gives you a detailed explanation. What about this technology? What is the basic working principle? In traditional multi-carrier communication systems, the entire system band is divided into several sub-channel carriers that are separated from each other ). There is a certain protection interval between carriers, and the receiver uses a filter to separate each su

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

In traditional multi-carrier communication systems, the entire system band is divided into several sub-channels (carriers) that are separated from each other ). There is a certain protection interval between carriers, and the receiver uses a filter to separate each sub-channel and then receives the required information. This can avoid mutual interference between different channels, but at the expense of frequency utilization. In addition, when the number of subchannels is large, it is almost imp

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

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

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

"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

than the Minn algorithm, which improves the accuracy and certainty of timing. However, in the case of large noise disturbance, the algorithm still has a large timing synchronization estimation error, and the stability of the synchronization estimation is still poor.Reference documentsPark B,choen H, KO E, et al. A novel timing estimation method for OFDM Systems[j]. IEEE commun.leet.2003,7 (5): 53-55.\[m (d) =\frac{\left | P (d) \right |} {r^{2} (d)}^

estimation will be affected greatly under the condition of low Snr.Reference documentsMinn H, Zeng M,bhargava V k.on timing offser estimation for OFDM Systems[j]. IEEE commun.lett.2000,4 (7): 242-244.\[m (d) =\frac{\left | P (d) \right |} {r^{2} (d)}^{2}\]\[p (d) =\SUM_{K=0}^{1}\SUM_{M=0}^{N/4 -1}r^{*} (D+m+\frac{nk}{2}) R (d+m+\frac{n}{4} + \frac{nk}{2}) \]\[r (d) =\sum_{k=0}^{1}\sum_{m=0}^{n/4-1}\left | R (d+m+\frac{n}{4} + \frac{nk}{2}) \right |^{

Objective:These days began to get ready to engage in OFDM and the like, do not move the first MATLAB simulation, here I will slowly update, is basically my own learning sentiment bar First, PRBSPRBS is the abbreviation for Pseudo random binary Sequence, meaning "pseudo-random binary sequence". The PRBS code has a "random" feature, is because in the PRBS stream, the binary number "0" and "1" is random, but it and the real meaning of the random code, th

First, WiFi-related basic concepts1. What is WiFiLet's take a look at how Baidu Encyclopedia is defined:Wi-Fi is a technology that can connect computers, handheld devices (such as pads, mobile phones) wirelessly to each other, in fact a high-frequency wireless signal . [1] Wireless is really a wireless network communication technology brand, held by the Wi-Fi Alliance. The aim is to improve interoperability among wireless network products based on the