Description: 很完善的一个OFDM仿真程序,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.-very sound one OFDM simulation program, which is in the form FUNCTION, Reproduction of OFDM mapping, IDFTDFT, synchronous (time-frequency synchronous) and channel estimation, and the estimated frequency offset a series of code. Platform: |
Size: 27733 |
Author:钟伟 |
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Description: This paper investigates the design of joint frequency
offset and carrier phase estimation of a multi-frequency time division
multiple access (MF-TDMA) demodulator that is applied to
a digital video broadcasting—return channel system via satellite
(DVB-RCS). The proposed joint estimation algorithm is based on
the interpolation technique for two correlation values in the frequency
and phase domains. This simple interpolation technique
can significantly improve frequency and phase resolution capabilities
of the proposed technique without increasing the number of
the correlation values. In addition, the overall block diagram of a
digital communications receiver for DVB-RCS is presented, which
was designed using the proposed estimation algorithms.
Index Terms—Carrier phase estimation, DVB-RCS, frequency
offset estimation, interpolation, joint estimation, MF-TDMA. Platform: |
Size: 501216 |
Author:吴大亨 |
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Description: 802.11a OFDM MATLAB仿真代码,包括OFDM映射,IDFT/DFT,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-802.11a OFDM MATLAB simulation code, including OFDM mapping, SINGLE/DFT, synchronous (time/frequency synchronization) and channel estimation, and the estimated frequency offset a series of code Platform: |
Size: 25600 |
Author:耿毅 |
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Description: This paper investigates the design of joint frequency
offset and carrier phase estimation of a multi-frequency time division
multiple access (MF-TDMA) demodulator that is applied to
a digital video broadcasting—return channel system via satellite
(DVB-RCS). The proposed joint estimation algorithm is based on
the interpolation technique for two correlation values in the frequency
and phase domains. This simple interpolation technique
can significantly improve frequency and phase resolution capabilities
of the proposed technique without increasing the number of
the correlation values. In addition, the overall block diagram of a
digital communications receiver for DVB-RCS is presented, which
was designed using the proposed estimation algorithms.
Index Terms—Carrier phase estimation, DVB-RCS, frequency
offset estimation, interpolation, joint estimation, MF-TDMA.-This paper investigates the design of joint frequencyoffset and carrier phase estimation of a multi-frequency time divisionmultiple access (MF-TDMA) demodulator that is applied toa digital video broadcasting-return channel system via satellite (DVB-RCS). The proposed joint estimation algorithm is based onthe interpolation technique for two correlation values in the frequencyand phase domains. This simple interpolation techniquecan significantly improve frequency and phase resolution capabilitiesof the proposed technique without increasing the number ofthe correlation values. In addition, the overall block diagram of adigital communications receiver for DVB-RCS is presented, whichwas designed using the proposed estimation algorithms.Index Terms-Carrier phase estimation, DVB-RCS, frequencyoffset estimation, interpolation, joint estimation, MF-TDMA. Platform: |
Size: 500736 |
Author:吴大亨 |
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Description: 《MIMO-OFDM关键技术的研究和完整仿真平台的建立》，建立了一个完整的MIMO-OFDM的仿真平台，为实际的硬件平台提供解决方案，给出性能评估。为建立这个完整的仿真平台，本文从MIMO-OFDM信号模型，提出系统实现的各个关键技术:帧同步和载波频偏估计、信道估计、采样同步和载波跟踪、空时/频编解码。- MIMO-OFDM key technology research and the establishment of a complete simulation platform , the establishment of a complete MIMO-OFDM simulation platform, for the actual hardware platform to provide solutions, given performance evaluation. For the establishment of the integrity of the simulation platform, this article from the MIMO-OFDM signal model, the system in all key technologies: frame synchronization and carrier frequency offset estimation, channel estimation, sampling synchronization and carrier tracking, space-time/frequency codecs. Platform: |
Size: 2463744 |
Author:李继龙 |
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Description: 在这篇论文中，我们提出一种新的时间偏移估计方法应用于OFDM系统。这里提出的估计是为了避免发生在Schmidl中的时间偏移估计方法中的歧义。通过仿真，所提出方案中的性能以均值和最小均方误差的形式说明。仿真结果表明：它与其它估计器相比在相当大的程度上有更小的均方误差。-In this paper, we propose a new time offset estimation method is applied to OFDM systems. Estimates presented here took place in order to avoid the time Schmidl offset estimation method of ambiguity. Through the simulation, the proposed program of performance to the mean and minimum mean square error of the form. The simulation results show that: it is estimated that compared with the other to a large extent there is a smaller mean square error. Platform: |
Size: 91136 |
Author:hehe |
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Description: 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.-To FUNCTION in the form of, reproduce OFDM mapping, IDFTDFT, synchronized (time and frequency synchronization), and channel estimation and frequency offset estimation and a series of codes. Platform: |
Size: 17408 |
Author:王琴 |
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Description: In this paper, we investigate the timing and carrier
frequency offset (CFO) synchronization problem in decode and
forward cooperative systems operating over frequency selective
channels. A training sequence which consists of one orthogonal
frequency-division multiplexing (OFDM) block having a tile
structure in the frequency domain is proposed to perform synchronization.
Timing offsets are estimated using correlation-type
algorithms. By inserting some null subcarriers in the proposed tile
structure, we propose a computationally efficient subspace decomposition-
based algorithm for CFO estimation. The issue of optimal
tile length is studied both theoretically and through simulations.
By judiciously designing the tile size of the pilot, the proposed
algorithms are shown to have better performance, in terms of
synchronization errors and bit error rate, than the time-division
multiplexing-based training method and the computationally demanding
space-alternating generalized expectation-maximization Platform: |
Size: 985088 |
Author:ashish |
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Description: In this paper, we investigate the timing and carrier
frequency offset (CFO) synchronization problem in decode and
forward cooperative systems operating over frequency selective
channels. A training sequence which consists of one orthogonal
frequency-division multiplexing (OFDM) block having a tile
structure in the frequency domain is proposed to perform synchronization.
Timing offsets are estimated using correlation-type
algorithms. By inserting some null subcarriers in the proposed tile
structure, we propose a computationally efficient subspace decomposition-
based algorithm for CFO estimation. The issue of optimal
tile length is studied both theoretically and through simulations.
By judiciously designing the tile size of the pilot, the proposed
algorithms are shown to have better performance, in terms of
synchronization errors and bit error rate, than the time-division
multiplexing-based training method and the computationally demanding
space-alternating generalized expectation-maximization Platform: |
Size: 728064 |
Author:ashish |
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Description: 802.11a OFDM MATLAB仿真代码，包含OFDM映射，IDFFT/DFT，同步(时间/频率同步)与信道估计，和频率偏移的估计等一系列代码
-802.11a OFDM MATLAB simulation code, including the OFDM mapping IDFFT/DFT synchronization (time/frequency synchronization) and the channel estimation and frequency offset estimation a series of code Platform: |
Size: 26624 |
Author:tiebos |
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Description: 根据软件无线电的思想，提出了一种新颖的数字信号处理算法，对QPSK信号的相位进行数字化处理，从而实现对QPSK信号的解调.该算法允许收发两端载波存在频差，用数字锁相实现收发端载波的同步，在频偏较大的情况下，估算频偏的大小，自适应设置环路的带宽，实现较短的捕获时间和较好的信噪性能。整个设计基于XILINX公司的ISE开发平台，并用Virtex-II系列FPGA实现。用FPGA实现调制解调器具有体积小、功耗低、集成度高、可软件升级、扰干扰能力强的特点，符合未来通信技术发展的方向。-According to the idea of software radio, a novel digital signal processing algorithm, the phase of QPSK digital signal processing, enabling the demodulation of QPSK signals. This algorithm allows the sending and receiving ends of the carrier frequency difference exists, using digital phase-locked to achieve synchronization of sending and receiving end of the carrier, in the case of large frequency offset, frequency offset estimation of the size, adaptive set the loop bandwidth to achieve shorter acquisition time and better noise performance. The whole design is based on the company XILINX ISE development platform, and Virtex-II series with the FPGA. FPGA realization of a modem with a small size, low power consumption, high integration, software upgrades available, the characteristics of strong interference interference, in line with the future direction of ICT development. Platform: |
Size: 64512 |
Author:马文 |
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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 of all, according to the characteristics of the short training word correlation calculation of the signal reaching the detector, when the detected correlation value is greater than the threshold of a certain frequency and that a signal arrives. Then, the correlation calculation according to the characteristics of the long training word, the initial estimate of the location of the OFDM symbol FFT window. The estimated position of the FFT window, the first small frequency offset estimation in the time domain, the small frequency offset compensation, the two long training word FFT operation integer frequency offset estimate, according to the result of the FFT operation. After the completion of these parameter estimates, data demodulation. The complete frequency offset compensation, and then based on the estimated FFT window position for the FFT operation to obtain a frequency domain data, demodulates the first data part. Then in a position corresponding to the pilot subcarriers extr Platform: |
Size: 124928 |
Author:章田 |
Hits:
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: 针对ＴＤ－ＬＴＥ ＰＲＡＣＨ信道信号ＥＶＭ测量实现复杂、实时性差、测量精度不高的问题，提出一种基于随机接入信号相关性、频偏估计、相位估计以及硬件相偏校准的ＥＶＭ求解算法，可以快速准确地进行ＥＶＭ测量。通过对比和仿真，验证了该实现方案的高效性和可行性。该算法已在ＴＤ－ＬＴＥ射频一致性测试仪表中得到应用-Implementation for TD-LTE PRACH channel signal EVM measurement of complex, real-time differential measurement accuracy is not high, is proposed based on the random access signal correlation, frequency offset estimation, phase estimation and hardware EVM phase offset calibration algorithm can EVM measurements carried out quickly and accurately. By comparing and simulation to verify the efficiency and feasibility of the implementation program. The algorithm has been applied in TD-LTE RF Conformance Test instrument Platform: |
Size: 521216 |
Author:杨佳琳 |
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Description: Time and Frequency Synchronization Techniques for
OFDM Systems operating in Gaussian and Fading
Channels: A Tutorial
The aim of this paper is to survey and compare
previous methods for Data-aided timing and frequency
synchronization of OFDM System. In the sequel, we propose a fast
and accurate FFT-based frequency offset estimation. The
synchronization techniques are examined in Gaussian andMultipath fading environments for comparison. The results of the
performance comparison are presented in terms of mean andmean-square error (MSE) obtained by simulations. The timing
offset estimator with best performance is chosen for system timingsynchronization. The FFT-based frequency offset estimation
method has significantly smaller MSE than others can beperformed using the same timing training symbol. Therefore,there is only one training symbol needed as preamble in whole
synchronization process.
Platform: |
Size: 340992 |
Author:Mohamed |
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Description: 接收端采用的算法和程序流程与发送端发送的OFDM符号的帧结构有关系。具体的帧结构，以及定时估计，频偏估计，剩余误差跟踪的算法可参考算法说明文档。这里对程序的流程进行说明。
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。
-The receiving end uses the algorithm and the program flow and the frame structure of the OFDM symbol transmitted by the sending end. Specific frame structure, and timing estimation, frequency offset estimation, residual error tracking algorithm can refer to the documentation. Here to illustrate the process of the program.
First, according to the characteristics of the short training word correlation operation, the signal reaches the detection, when the correlation value is greater than the threshold of a certain number of times, that there is a signal to reach. Then, according to the characteristics of the long training word, the correlation operation is carried out, and the initial position of the OFDM symbol FFT is estimated. The estimated position of the FFT window, first in the time domain for small frequency offset estimation, two long training word for small frequency offset compensation, the FFT operation. According to the result of FFT for integer frequency bias estimation. Af Platform: |
Size: 34816 |
Author:shinfer |
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Description: ：LTE(Long Term Evolution，长期演进)系统中的小区初始搜索过程通过分别检测主同步信号(Primary Synchronization Signal，PSS)和辅同步信号(Secondary Synchronization Signal，SSS)来完成，搜
索结果包括小区组ID、符号定时、频偏估计、组内小区ID以及帧定时[1]。然而，若接收信号 1IDN 2IDN
中存在整数倍频偏，则由于时域的相位旋转，主同步信号将很难用传统的相关算法检测到。提出一种主同步信号与整数倍频偏联合检测的方法，即使存在整数倍频偏，也能得到正确的符号定时。辅同步信号采用的是非相干的差分相关检测[2]，仿真表明，与传统的匹配滤波算法相比，可以有效的对抗信道时延扩展和载波频偏，适用于高速场景下时分双工(Time Division Duplex，TDD)LTE系统的同步。-In LTE systems, the initial cell search process is completed by detecting the primary synchroniza-tion signal and the secondary synchronization signal. The searching results include cell ID group, symbol timing, frequency offset estimation, intra group cell ID and frame timing[1]. However, if integer frequency offset presents in the received signal, due to time-domain phase rotation, the primary synchronization signal will be difficult to detected using the conventional correlation algorithm. A new joint detection method for integer frequency offset and primary synchronization signal is proposed, which can get the correct symbol timing even if the presence of integer frequency offset. Secondary synchronization signal is processed using the differential non-coherent correlation detection method[2]. Simulations show that compared with the tradi-tional matched filtering algorithms, it can effectively combat the channel delay spread and carrier frequency offset and especially suitable for Platform: |
Size: 257024 |
Author:imc_lte |
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Search - time offset estimation