Description: Channel estimation for OFDM systems based on comb-type pilot arrangement in frequency selective fading channels
一篇信道估计的经典文章-Channel estimation for OFDM systems based on comb-type pilot arrangement in frequency se lective fading channels a channel estimation of the classic article Platform: |
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Author:李瑞锋 |
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Description: Channel estimation for OFDM systems based on comb-type pilot arrangement in frequency selective fading channels
一篇信道估计的经典文章-Channel estimation for OFDM systems based on comb-type pilot arrangement in frequency se lective fading channels a channel estimation of the classic article Platform: |
Size: 881664 |
Author:李瑞锋 |
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Description: ofdm信道特性
Channel transmission simulator
Channel transmission simulator
％
％ inputs:
％ sig2 - noise variance
％ Mt - number of Tx antennas
％ Mr - number of Rx antennas
％ x - vector of complex input symbols (for MIMO, this is a matrix, where each column
％ is the value of the antenna outputs at a single time instance)
％ H - frequency selective channel - represented in block-Toeplitz form for MIMO transmission
％ N - number of symbols transmitted in OFDM frame
％
％ outputs:
％ y - vector of channel outputs (matrix for MIMO again, just like x matrix)
％ create noise vector sequence (each row is a different antenna, each column is a
％ different time index) note: noise is spatially and temporally white-channel characteristics of OFDM Channel transmission simulatorChannel transmission simulator inputs: sig2- noise variance Mt- number of Tx antennas Mr- number of Rx antennas x- vector of complex input symbols (for MIMO, this is a matrix, where each column is the value of the antenna outputs at a single time instance) H- frequency selective channel- represented in block-Toeplitz form for MIMO transmission N- number of symbols transmitted in OFDM frame outputs: y- vector of channel outputs (matrix for MIMO again, just like x matrix) create noise vector sequence (each row is a different antenna, each column is a different time index) note: noise is spatially and temporally white Platform: |
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Author:sunxu |
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Description: OFDM下的信道估计，在频率选择性rayleigh信道下五条多径下测试，并作出信道估计性能曲线-OFDM under channel estimation in frequency selective Rayleigh fading trail of more than five tests, and channel estimation performance curve Platform: |
Size: 10240 |
Author:韩聪 |
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Description: 信道描述，计算冲激响应函数，为频选衰落信道，用于MIMO或ＭＩＭＯ－ＯＦＤＭ系统-Channel description, calculation of impulse response function, for Frequency-Selective Fading Channels for MIMO or MIMO-OFDM system Platform: |
Size: 1024 |
Author:刘斐 |
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Description: 国外的详细的OFDM设计过程文档，对学习OFDM非常有帮助，并且有仿真结果。-This report discusses the design and implementation of an OFDM modem for a simplex communication
between two PCs over a frequency selective channel. First a brief introduction is
provided by explaining the backrground and the specification of the project. Then the report
deals with the system model. Each block of the OFDM system is described (IFFT/FFT, cyclic
prefix, modulation/demodulation, channel estimation, bit loading). In the following section, the
system architecture is analysed. The transmission protocol, as well as the system parameters
are explained in details. Then, the DSP implementation is discussed. Finally, the results are
provided in the last chapter. Platform: |
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Author: |
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Description: Orthogonal Frequency Division Multiplex (OFDM) system has inherent advantage over single
carrier system in frequency-selective fading channel. It has been adopted by various standards in recent
years including DSL and 802.11a wireless LAN standards. Platform: |
Size: 652288 |
Author:redami |
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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: This paper introduces linear constellation precoding
(LCP) for OFDM transmissions over frequency-selective
fading channels. Exploiting the correlation structure
of OFDM subchannels, and choosing system parameters
properly, we first perform optimal subcarrier grouping
to divide the set of correlated subchannels into subsets.
Within each subset, a non-redundant constellation-specijic
unitary precoder is then designed to achieve maximum
multipath diversity and coding gains. While greatly reducing
the decoding complexity and simplifiing the LCP
design, subcarrier grouping offers optimal perjormance by
maximizing multipath diversity and coding gains. In addition,
the proposed system does not sacrifice the transmission
rate. Analytic evaluation and corroborating simulations
reveal its pe$ormance merits. Platform: |
Size: 460800 |
Author:ashish |
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Description: the comb pilot aided channel estimation in ofdm modulation is considered. the power of pilot subchannels is under the control.
The data experience frequency selective channel then the AWGN noise is added to make the situation worse. The bit error rate is ploted versus SNR. Platform: |
Size: 508928 |
Author:Muhammad Ali Aftab |
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Description: As a multi-carrier modulation scheme, Orthogonal Frequency Division Multiplexing (OFDM)
technique can achieve high data rate in frequency-selective fading channels by splitting a
broadband signal into a number of narrowband signals over a number of subcarriers, where
each subcarrier is more robust to multipath. The wireless communication system with multiple
antennas at both the transmitter and receiver, known as multiple-input multiple-output
(MIMO) system, achieves high capacity by transmitting independent information over different
antennas simultaneously. The combination of OFDM with multiple antennas has been
considered as one of most promising techniques for future wireless communication systems. Platform: |
Size: 2609152 |
Author:ashish |
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Description: Ajey, S., B. Srivalli, et al. (2010). On performance of MIMO-OFDM based LTE systems. Wireless Communication and Sensor Computing, 2010. ICWCSC 2010. International Conference on.
4G wireless systems predominately employ multiple input multiple output (MIMO) with an orthogonal frequency division multiplexing (OFDM) system. Like other 4G systems long term evolution (LTE) also employs MIMO-OFDM physical layer. MIMO helps in increasing the throughput whereas OFDM converts a frequency selective fading channel to multiple flat fading sub-channels facilitating easy equalization. It is proposed that LTE system should mandatorily support 2Ã — 2 MIMO setup. Our paper focuses on the performance of such a LTE system with two transmit antennas and two receive antennas in a frequency selective fading environment. Platform: |
Size: 311296 |
Author:Lakmali |
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Description: Though the total channel is a frequency selective channel, the channel experienced by each subcarrier in an OFDM system is a flat fading channel with each subcarrier experiencing independent Rayleigh fading. Platform: |
Size: 2048 |
Author:azer |
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Description: 正交频分复用(OFDM)是第四代移动通信的核心技术,它是实现宽带无线通信和多媒 体业务发展的基础。对OFDM 技术的基本原理，关键技术以及实现进行了研究，并且通过 matlab 中的通信仿真系统simulink 对OFDM 系统进行了模拟和分析，直观和形象地得到了 OFDM 系统在时域和频域的传输性能，得出的结果表明OFDM 系统可以明显地表现出抗多 径效应引起的频率选择性衰落和提高了频谱利用率，这一特性使得它能够在高数据传输速率 的无线信道中发挥优势。-Orthogonal Frequency Division Multiplexing (OFDM) is the fourth generation mobile communication core technology, which is broadband wireless communications and multimedia development. The basic principle of OFDM technology, key technology and implementation have been studied, and by matlab simulink simulation system in the OFDM communication system was simulated and analyzed, intuitive, and get the image of the OFDM system in time domain and frequency-domain transmission performance , the results show that OFDM system can be apparent in the anti-multipath effect caused by frequency selective fading and improve the spectrum efficiency, this allows it to transmit at high data rate wireless channel advantage. Platform: |
Size: 258048 |
Author:foxlili |
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Description: the use of coherent space-frequency coding in orthogonal frequency division multiplexing (OFDM)-based frequency-selective multiple-input multiple-output (MIMO) antenna fading channels has been proposed. Acquiring knowledge of the fading coefficients in a MIMO channel is already very challenging in the frequency-flat (fast) fading case. In the frequency-selective case, this task becomes significantly more difficult due to the presence of multiple paths, which results in an increased number of parameters to be estimated. In this paper, we address code design for noncoherent frequency-selective MIMO-OFDM fading links, where neither the transmitter nor the receiver knows the channel. We derive the code design criteria Platform: |
Size: 32768 |
Author:sourov |
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Description: Matlab code which implements MB-OFDM transmission block as per ECMA 368 standard.
OFDM over frequency selective wireless channels
simulation code for Peak-to-Average Power Ratio (PAPR) reduction in MIMO OFDM/A system using CMA
This is an OFDM simulation that gives you the PAPR, BER, and the PSD before and after the SSPA.
the program distribute an amount power among ofdm subchannel to make the capacity of a channel as ma
Representation of OFDM signal with PAPR reduction using Clipping and SLM Techniques.
The complete project of OFDMA system. It tries to maximize the network capacity.
Link and system level simulator for OFDM based wireless broadband systems
Ultrawideband (UWB) multiband OFDM physical layer with fixed-point transmitter/receiver modeling.
Platform: |
Size: 858112 |
Author:Sina |
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Search - ofdm in frequency selective