Description: 本文首先概述了OFDM 的原理、特征和关键技术，介绍了系统需要的几种同步。然后就同步误差对系统性能的影响进行了简单的分析，表明定时偏差和采样频率偏差将会引入码间干扰，载波频率偏差导致载波间干扰的发生。因此，在OFDM系统接收机中定时的确定、载波频率偏差和采样频率偏差的纠正是信号恢复的关键。之后对OFDM系统同步的几种实现方法进行了介绍，分析了各同步方法的性能。-The paper first outlines the principles of OFDM, features and key technologies, the system needs to introduce several synchronization. Synchronization error and then the impact on system performance for a simple analysis, show that the timing deviation and the sampling frequency deviation will introduce inter-symbol interference, the carrier frequency deviation led to the occurrence of ICI. Therefore, in OFDM system receiver to determine the timing, carrier frequency offset and sampling frequency offset correction signal to restore the key. After the OFDM system to achieve synchronization of several methods of introduction, an analysis of the performance of the synchronization method. Platform: |
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Author:dajinyu |
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Description: 这是一个非常好的用于OFDM的基于CP的 最大似然符号定时同步和载波同步的MATLAB仿真程序，经本人深入阅读吸收经典文献，反复编程调试而提炼而成，代码精炼有序，绝对没有错误，由此程序仿真得到的同步曲线与经典文献完全一致。同仁们阅读此程序一定受益匪浅！
这里不吝成果，特上载与诸位网友共享。也欢迎同仁们提供更多的优秀程序。
由于文献要求采用N＝1024个子载波的OFDM，运行此程序需2分钟－3分钟的时间。
-This is a very good CP for OFDM-based maximum likelihood symbol timing synchronization and carrier synchronization of the MATLAB simulation program, after I read the absorption of classical literature in depth, repeated programming and debugging derived, code refining orderly, absolute no mistake, this process has been synchronized simulation curve is fully consistent with classical literature. Tongren have read this procedure will definitely benefit! Spared the outcome here, especially to upload to share with you friends. Tongren also welcome to provide more excellent program. Documentation required as a result of N = 1024 sub-carrier OFDM, to run this process will take 2 minutes-3 minutes. Platform: |
Size: 1024 |
Author:黄翔东 |
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Description: 值得深刻阅读的基于CP的OFDM同步程序
这是一个非常好的用于OFDM的基于CP的 最大似然符号定时同步和载波同步的MATLAB仿真程序，经本人深入阅读吸收经典文献，反复编程调试而提炼而成，代码精炼有序，绝对没有错误，由此程序仿真得到的同步曲线与经典文献完全一致。同仁们阅读此程序一定受益匪浅！ 这里不吝成果，特上载与诸位网友共享。也欢迎同仁们提供更多的优秀程序。 由于文献要求采用N＝1024个子载波的OFDM，运行此程序需2分钟－3分钟的时间。
-Worthy of profound reading of the CP-based OFDM synchronization process this is a very good CP for OFDM-based maximum likelihood symbol timing synchronization and carrier synchronization of the MATLAB simulation program, after I read the absorption of classical literature in depth, repeated programming and debugging extracted from the symbol of refined and orderly, there is no error, this procedure has been synchronized simulation curve is fully consistent with classical literature. Tongren have read this procedure will definitely benefit! Spared the outcome here, especially to upload to share with you friends. Tongren also welcome to provide more excellent program. Documentation required as a result of N = 1024 sub-carrier OFDM, to run this process will take 2 minutes-3 minutes. Platform: |
Size: 1024 |
Author:张华 |
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Description: The Matlab code privided will generate OFDM symbol and will save the received symbols in two log file. Agorithm will determine Start point and carrier frequency off-set as a Synchronization block. Platform: |
Size: 2048 |
Author:aliradian |
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Description: 该模型实现了一个通用的OFDM TX和RX，这是不依赖于任何特定的行业标准。该模型的目标是开发和研究不断（不是“突发”）载波同步和定时跟踪方案。该技术纳入然后可以扩展和修改，以标准的具体通讯套件。该模型采用了“收购”技术，它利用了循环前缀相关属性，以赶在试图完成罚款跟踪算法一帧的边界粗略的估计。该模型实现了一个16点64循环前缀的OFDM载波波形。在OFDM符号有16个飞行员，3后卫音（0，带边幅），并使用45 QAM的剩余数据流4。
这包括最新型的衰落信道，误码率计算，并改善控制回路动态。-This model implements a generic OFDM TX and RX, which is not tied to any particular industry standard. The objective of this model is to develop and explore a continuous (not “bursty”) carrier and timing tracking synchronization scheme. The techniques incorporated can then be extended and modified to suite specific communications standards. The model uses an “acquisition” technique that exploits the correlation properties of the cyclic prefix to get a rough estimate of the frame boundary before attempting to accomplish the fine tracking algorithms. The model implements a 64 carrier OFDM waveform with a 16 point cyclic prefix. The OFDM symbol has 16 pilots, 3 guard tones (0 amplitude at band edge) and uses 4 QAM for the 45 remaining data streams.
This latest model includes a fading channel, BER computation, and improved control loop dynamics.
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Size: 293888 |
Author:zaaa |
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Description: carrier_count= 200
bits_per_symbol = 2
symbols_per_carrier = 50
loop=10
num=5
循环次数 10
子载波数 200
位数/ 符号 2
符号数/ 载波 50
训练符号数 5
循环前缀长度 T/4
调制方式 QAM
多径信道数 2（缺省）
信道最大时延 5 (单位数据符号)
仿真条件 收发之间严格同步
一个OFDM系统 在瑞利信道环境下 包括信道估计 比较适合初学者-carrier_count = 200 bits_per_symbol = 2 symbols_per_carrier = 50 loop = 10 num = 5 10 cycles 200 of the median number of subcarriers/symbol and the number of symbols of 2 /50 of the carrier the number of training symbol cyclic prefix length of 5 T/4 modulation QAM Number of multi-path channel 2 (default) 5 channel maximum delay (in the data symbol) strict synchronization between the simulation conditions receive an OFDM system in Rayleigh channel environment, including more suitable for channel estimation beginner Platform: |
Size: 2048 |
Author:Mir Ge |
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Description: 多天线正交频分复用(MIMO-OFDM,Multiple-Input and Multiple-Output Orthogonal Frequency Division Multiplex)系统中,精确的符号定时同步可使接收端解调数据时消除载波频率偏移和符号间干扰。而由于MIMO空间信道复杂度较高,使得单天线OFDM系统的同步方法不能直接应用于MIMO-OFDM系统中。提出的两步同步方法首先利用时域导频作为第一步同步进行粗同步,然后利用循环交织前缀作为第二步同步对每一个MIMO-OFDM符号进行同步偏差调整。需要指出的是,两次同步过程均可以产生尖锐的相关峰,使得同步精度大为提高。-Accurate timing synchronization of symbol is important for MIMO-OFDM system,and it can eliminate the integral frequency shift of carrier and intersymbol interference.Two-step timing synchronization method is proposed in this thesis.First,the time-domain pilot is employed to obtain coarse timing synchronization,then the interleaved cyclic prefix and maximum likelihood estimation method are adopted to adjust the synchronization difference,through which the correlational characteristic of that window could be ... Platform: |
Size: 807936 |
Author:王睿 |
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Description: 最大似然方法联合实现符号定时同步和载波同步仿真 -This is a very good CP for OFDM-based maximum likelihood symbol timing synchronization and carrier synchronization of the MATLAB simulation program, Platform: |
Size: 1024 |
Author:liu |
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Description: 值得深刻阅读的基于CP的OFDM同步程序这是一个非常好的用于OFDM的基于CP的 最大似然符号定时同步和载波同步的MATLAB仿真程序，经本人深入阅读吸收经典文献，反复编程调试而提炼而成，代码精炼有序序，绝对没有错误，由此程序仿真得到的同步曲线与经典文献完全一致。同仁们阅读此程序一定受益匪浅！ 这里不吝成果，特上载与诸位网友共享。也欢迎同仁们提供更多的优秀程序。 由于文献要求采用N＝1024个子载波
-Worthy of profound reading of the CP-based OFDM synchronization program which is a very good based on the CP maximum likelihood symbol timing synchronization and carrier synchronization for OFDM MATLAB simulation program, after I read in-depth absorption of classical literature, repeated programming and debugging and refining made, the code refined and orderly sequence is absolutely no mistake, this program simulation synchronization curves and classic literature is exactly the same. Colleagues to read this program must benefit Generous achievements, special upload to share with you friends. Also welcome colleagues to provide more excellent program. Because the literature require the use of N = 1024 subcarriers Platform: |
Size: 1024 |
Author:勇敢 |
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Description: 一种新的符号定时和载波频率同步算法,该算法将OFDM符号分成几部分。它使用相关性和积累在几个OFDM同步算法对OFDM系统基于试点,使用前言快速、准确获取信号,在有限的时间建立同步,利用导频跟踪同步信息-A new symbol timing and carrier frequency synchronization algorithm is presented and the algorithm divides the OFDM symbol into several parts. It uses correlation and accumulation in several OFDM a synchronization algorithms for OFDM system based on pilot, using the preamble to fast and accurate acquire signal, establish synchronization in the limited time, and using pilot to track synchronization information Platform: |
Size: 1267712 |
Author:wujueying |
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Description: 该模型实现一个不依赖于任何特定的行业标准通用的连续同步OFDMOFDM模型TX和RX。这个模型的目的是开发和探索出一条连续的（而不是“突发”）的载波和定时同步跟踪计划。然后使用该技术可以扩展和修改特定通信标准。-This model implements a generic OFDM TX and RX, which is not tied to any particular industry standard. The objective of this model is to develop and explore a continuous (not “bursty”) carrier and timing tracking synchronization scheme. The techniques incorporated can then be extended and modified to suite specific communications standards. The model uses an “acquisition” technique that exploits the correlation properties of the cyclic prefix to get a rough estimate of the frame boundary before attempting to accomplish the fine tracking algorithms. The model implements a 64 carrier OFDM waveform with a 16 point cyclic prefix. The OFDM symbol has 16 pilots, 3 guard tones (0 amplitude at band edge) and uses 4 QAM for the 45 remaining data streams. Platform: |
Size: 330752 |
Author:林真天 |
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Description: A Novel Time and Frequency Synchronization Scheme for OFDM Systems
A new training symbol is designed and a novel
time and frequency synchronization scheme for orthogonal frequency division multiplexing systems is proposed. The time synchronization is accomplished by using the symmetric conjugate of the training symbol in time domain and the frequency synchronization is finished by utilizing the good
autocorrelation of the training symbol in frequency domain.
The simulation results show that compared with conventional schemes, the proposed scheme gives a more accurate estimate of symbol timing and carrier frequency offset and provides a
wider acquisition range for the carrier frequency offset.1 Platform: |
Size: 321536 |
Author:Mohamed |
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Description: 正交频分复用(OFDM)技术是一种可以有效对抗符号间干扰(ISI)的高速数据传输技术。OFDM是一种特殊的多载波调制方式，它的基本思想是将高速传输的数据流通过串/并转换，变成在若干个正交的窄带子信道上并行传输的低速数据流。OFDM接收机有三个关键技术：信道估计技术，降低峰均比(PAPR)技术和同步技术。OFDM技术能有效的对抗多径衰落等，有着诸多的优点，但是OFDM有一个发展瓶颈，即OFDM信号的峰均功率比很大，很容易导致OFDM信号的交调失真和系统性能的下降。因而如何降低OFDM信号的峰均功率比一直是OFDM技术的一个研究热点问题。论文针对上述问题，重点研究了降低OFDM信号的峰均功率比的SLM与PTS算法，并利用Matlab对算法进行了仿真研究，并对仿真结果进行了分析。-Orthogonal frequency division multiplexing (OFDM) is a high-speed data transmission technology that can effectively combat inter-symbol interference (ISI). OFDM is a special multi-carrier modulation method, its basic idea is to high-speed transmission of data stream through the serial/parallel conversion, in a number of orthogonal narrowband sub-channel parallel transmission of low-speed data stream. OFDM receivers have three key technologies: channel estimation techniques, reduced peak-to-average ratio (PAPR) techniques and synchronization techniques. OFDM technology can effectively combat multipath fading, etc., there are many advantages, but OFDM has a bottleneck in development, that is, OFDM signal peak power ratio is large, it is easy to lead to OFDM signal intermodulation distortion and system performance degradation. Therefore, how to reduce the peak-to-average power ratio of OFDM signal has been a hot topic in OFDM technology. In this paper, the SLM and PTS algorithms for reduc Platform: |
Size: 142336 |
Author:num113 |
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Description: One of the major challenges which prevents the coordinated multipoint (CoMP) communications concept from being widely deployed in new cellular systems is timing synchronization. In order to achieve the gains promised by CoMP systems, the user equipments’ (UEs) signals in uplink (UL) or the base stations’ (BSs) signals in downlink (DL) should be synchronized such that the time difference of arrivals (TDOAs) do not exceed the cyclic prefix (CP) length of the transmitted signals; Otherwise the system suffers from unavoidable integer time offsets. These offsets lead to asynchronous interference in terms of inter-carrier, inter-block and inter-symbol interference (ISI). This limits the percentage of area within a cell which can be covered by cooperation and imposes an upper bound on this area. In this paper, we investigate this problem in the UL and by using geometrical and semi-analytical approaches, we define this upper bound. Also, by characterizing an accurate mathematical model for the asynchronous interference in Rayleigh fading channels, we were be able to employ a standard MMSE-based receiver that mitigates this interference. Furthermore, a typical joint channel and delay estimation block is incorporated into the receiver to examine its performance with estimation errors. Platform: |
Size: 1869319 |
Author:ahamza |
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Search - symbol and carrier synchronization for OFDM