Description: 主动式反孤岛效应方法中的主动频率偏移法，通过matlab中的Embedded function编写的验证函数-Active anti-islanding methods active frequency offset method, through the Embedded function matlab written verification function Platform: |
Size: 9216 |
Author:郭风铃 |
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Description: 针对OFDM系统中的频偏模型进行建模，并比较OFDM系统在不同频偏下的误比特率性能。-Making the frequency offset moddling for the OFDM system and then compare the bit error rate performance under different frequency offset. Platform: |
Size: 6144 |
Author:huangwei |
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Description: 首先根据短训练字的特性进行相关运算，进行信号到达检测，当检测到相关值大于门限一定次数后，认为有信号到达。然后根据长训练字的特性，进行相关运算，进行OFDM符号FFT窗口起始位置的估计。估计出FFT窗口的位置后，先在时域进行小频偏的估计，将两个长训练字进行小频偏补偿后，进行FFT运算，根据FFT运算的结果进行整数倍频偏的估计。这些参数估计完成后，就可以进行数据解调了。先对数据部分进行完整的频偏补偿，然后根据估计的FFT窗口位置进行FFT运算得到频域的数据，进行解调。然后在对应于导频的子载波位置上提取出导频信息，根据导频信息估计出剩余定时误差以及剩余的信道响应误差，将误差量送入环路进行跟踪。当收到所有数据后，重新回到信号到达检测状态，进行下一次信号到达的检测和信号接收。-First, according to the characteristics of the short training word correlation operation, the signal reaching the detector, when the detected correlation value is greater than the threshold after a certain number of times that a signal arrives. And then the characteristics of long training word, the correlation operation for the FFT window starting position of an OFDM symbol estimate. The estimated position of the FFT window, the first small frequency offset in the time domain estimation, the two long training word small frequency offset compensation, the FFT operation, the FFT result of the operation for integer frequency offset estimate. These parameter estimation is completed, the data can be demodulated on. The first portion of the data for a complete frequency offset compensation, and based on the estimated FFT window position of the FFT operation to obtain frequency domain data, demodulated. Then corresponding to the position of the pilot subcarriers are extracted on pilot inform Platform: |
Size: 11264 |
Author:wangkai |
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Description: In this paper, we present and analyze efficient frame synchronization and frequency offset compensation scheme with ternary sequences for an orthogonal frequency division multiplexing (OFDM) system in Rayleigh fading channels. Frame
synchronization is an essential procedure for normal operation of
the OFDM system because of sensitivity to synchronization errors. And when there are frequency offsets in OFDM frame, the loss of
orthogonality occurs and the interference problem among several subcarriers is introduced. These fact leads to the requirement for joint implementation of the frame synchronization and frequency offset compensation. Platform: |
Size: 1581056 |
Author:Joel |
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Description: 一个mc-cdma的程序，存在频率偏移和多普勒的情况下的同步问题-Mc-cdma a procedure, there is a frequency offset and Doppler in case the synchronization Platform: |
Size: 1024 |
Author:小王 |
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Description: 基于matlab的OFDM仿真程序；
我再论坛找了很多OFDM的代码和文章,但总有遗患,为什么呢原因是大部分只有简单的映射,IDFTDFT变换等等,但主要的同步和信道估计去没有人提出来,甚至做出来..
现在我终于找到了一份,它以FUNCTION的形式,再现了OFDM映射,IDFTDFT,同步(时间频率同步)和信道估计,以及频率偏移的估计等一系列代码.-Based on the OFDM matlab simulation program I' ll find a lot of forums and articles OFDM code, but there are left suffering, why because most only simple mapping, IDFTDFT transformation, etc., but the main synchronization and channel estimation to no one proposed, and even do it .. and now I finally found a copy of it in the form FUNCTION, Reproduction of OFDM mapping, IDFTDFT, synchronous (time and frequency synchronization) and channel estimation, and the estimated frequency offset a series of code. Platform: |
Size: 26624 |
Author:qinxuechen |
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Description: 时间同步后即可确定每帧数据的起始位置，这样就能完整的截取下每一帧。但是，数据中还带有频偏信息。在常规的通信系统中，多普勒很小仅仅会带来很小的频偏，但是在大多普勒的情况下，频偏将非常大，20马赫的速度将会带来将近34K的频偏。因此，如何很好的纠正频偏即为本系统的难点。
OFDM中，我们将大于子载波间隔倍数的频偏称为整数倍频偏，而将小于一个子载波间隔的频偏称为小数倍频偏。频偏矫正精度只要能保证小于十分之一倍的子载波间隔，频偏就不会对均衡和解调造成影响。本文中我们借鉴这种思想，由于硬件资源限制，我们将在接收端做64点FFT，即相当于将频域划分为64份，我们将小于 的频偏称为小数倍频偏，将 整数倍的频偏称为整数倍频偏。本程序即基于SCHIMDL经典方法完成小数倍频偏纠正-After time synchronization can determine the starting position of each frame data, so you can complete the interception of each frame. However, in the data with frequency information. In conventional communication systems, doppler small will bring only small deviation, but in the case of most of the doppler, frequency PianJiang is very large, 20 Mach speed will lead to deviation of nearly 34 k. Therefore, how to good to correct deviation is the difficulty of this system.
OFDM, we will be bigger than the sub-carrier spacing ratio of frequency deviation is called the integer frequency offset, and the interval will be less than a child carrier frequency offset is called decimal frequency doubling. Deviation is less than one over ten times as long as can guarantee accuracy of sub-carrier spacing, deviation will not affect balance and demodulation. This article, we draw lessons from the idea, due to the limited hardware resources, we will do 64 points FFT at the receiving end, which is equ Platform: |
Size: 14402560 |
Author:Nico_S |
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Description: 频偏估计算法利用已经完成定时同步的同一个训练序列来完成小数频偏估计和整数频偏估计。-Offset estimation algorithm uses the same timing synchronization has completed a training sequence to complete the fractional frequency offset estimation and integer frequency offset estimation. Platform: |
Size: 77824 |
Author:陶金 |
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Description: 单相光伏并网发电系统电压前馈控制和有源频率偏移（AFD）孤岛检测法的simulink仿真模型，初步实现了并网电流与电网电压的同频同相，AFD孤岛检测方法采用S函数给出，检测功能基本实现。-Single-phase grid-connected PV system voltage feedforward control and active frequency offset (AFD) simulink simulation model islanding detection method, the initial realization of grid current and the grid voltage of the same frequency and phase, AFD islanding detection method using the S function to out detection realized. Platform: |
Size: 13312 |
Author:Mr. ZENG |
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Description: 认知无线电系统中存在载波频偏的OFDM频谱感知技术1001-0548(2013)03-0355-05-OFDM Signal Sensing Scheme for Cognitive Radio in the Presence of Carrier
Frequency Offset. Platform: |
Size: 772096 |
Author:wang |
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Description: bpsk的调制与解调的过程，并采用卷积码，讨论其误码性能随着其功率、频偏、相偏而变化.-bpsk modulation and demodulation process and using convolutional codes, to discuss its error performance with its power, frequency offset, phase offset changes. Platform: |
Size: 1024 |
Author:wangke |
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Description: 将盲估计利用到OFDM系统的频偏估计上，仿真后能有效的估计频偏-The blind use to estimate the frequency offset estimate OFDM system simulation can effectively estimate the frequency offset Platform: |
Size: 5120 |
Author:gaoanqin |
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