ofdm modulation

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

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

PCM (Pulse-code modulation) Pulse coding modulation, pcm Pulse Coding modulation In audio processing, we often hear PCM data. What is PCM Data?PCM data is a digital signal after the analog signal passes through PCM. PCM is the process of converting the audio signal from analog signal (time continuous, value continuous) to digital signal (time discrete, value dis

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

and demodulation techniques are described below.Quadrature amplitude Modulation (QAM)In modern communication, it has been one of the focus of attention to improve the spectrum utilization. Quadrature amplitude modulated QAM (quadrature amplitude modulation) is a kind of modulation method with high frequency spectrum utilization, which has been widely used in med

standards. 802.1lb uses the KNN modulation technology to increase the data transmission rate, up to 11 Mbit/s. However, if the transmission rate exceeds 11 Mbit/s, it is very difficult to implement a more complex balance and modulation function to combat multi-path interference. Therefore, in order to promote the development of the wireless LAN, The 802.1l Working Group also introduced 0ofdm

Communication Algorithm 7: Communication System Algorithm Design, bit rate, spread spectrum, modulation method algorithm selection, communication system modulation method 1. Rate Matching: Bit Rate Selection Channel environment: AWGN Signal-to-Noise Ratio: SNR Bit Rate R: 1/2, 1/3, 1/4, 1/8 MATALB simulation architecture: Source bit + convolution code/Turbo (1/3) + Rate Matching (different R) + PSK

. However, this is generally not true in discrete time domains unless we use an infinitely large sample Value Point N or at least one convolution signal is cyclical (in this case, signals can be convolution by circumference ). Because we can only use a limited sample value of N, we can only use the cyclic prefix to make the OFDM Information Code appear periodically in the time zone we are interested in. The sample value of the circular expansion infor

Ask modulation simulation circuit:Device Selection:Select the signal source of the voltage-controlled sine wave in the sources->controlled_valtage_sources->voltage_controlled_sine_wave.Parameter settings:Set the signal generator to produce 1KHz, duty-free ratio 50%, amplitude of 5V square wave signal.Set the voltage control sine wave signal source control array -5v corresponding frequency 0hz,5v corresponds to 10khz,output peak low value = 0v,output P

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

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

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

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