共查询到18条相似文献,搜索用时 156 毫秒
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对基于导频的信道估计中的插值算法,包括线性、高斯、变换域、低通滤波及三次样条插值算法的性能、特点进行分析比较。其中,三次样条插值算法在对复杂信道的估计方面,具有更好的性能和灵活性。最后,给出三次样条插值利于工程实现的简便算法。 相似文献
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以MIMO—OFDM系统为研究对象,通过设计正交导频进行导频辅助信道估计,对数据点的信道响应进行线性内插、三次样条插值和二次曲线拟合算法,并通过Matlab进行计算机仿真,对这些算法的BER性能进行比较。结果表明:随着信噪比(SNR)的增加,三次样条(Spline)内插和线性内插性能要远好于二次曲线拟合导频估计方法。 相似文献
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OFDM系统中的导频插值算法研究 总被引:1,自引:0,他引:1
OFDM系统中,由于Doppler频移以及多径的影响,信道是变的,为了消除信道对传输信号的影响,需要对信道进行估计。现有的信道估计算法很多,每种算法都有其使用条件和适用范围,其中导频插值算法起着至关重要的作用。文章对现有OFDM系统中的导频插值算法进行了研究,对其仿真性能进行了分析,并对各种算法的性能进行了比较。 相似文献
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正交频分复用(OFDM,Orthogonal Frequency Division Multiplexing)技术是长期演进(LTE,Long Term Evolution)的核心技术之一.目前,基于导频的信道估计是OFDM系统中信道估计的常用方式.在基于导频的信道估计方式下,结合LS估计算法提出了一种下向插值算法(DWI).在LTE信道模型及导频结构下,通过MATLAB仿真工具,将该算法和现有各种算法的性能进行了比较和分析.仿真结果表明,使用结合LS估计算法和DWI算法的OFDM系统信道估计机制,具有复杂度低、易于实现的优点. 相似文献
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介绍MIMO-OFDM系统中几种基于导频的信道估计方法。首先研究了单天线OFDM系统的信道估计算法。一方面重点关注三种估计准则的原理,仿真表明LMMSE准则具有最佳的性能;另一方面介绍了几种插值的方法用来恢复非导频处的信道信息。 相似文献
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Chuan-Wang Chang Ho-Lung Hung Shu-Hong Lee Jyh-Horng Wen 《Wireless Personal Communications》2011,59(2):345-360
Pilot-aided channel estimation in orthogonal frequency division multiplexing (OFDM) systems often needs an interpolation technique
to construct the channel frequency response on nonpilot subcarriers. Many studies on interpolations have been published; however,
the performance of interpolations such as cubic spline interpolation and linear interpolation is limited by either the number
or the position of the pilot subcarriers. This paper proposes an analytic interpolator developed using a linear least square
criterion to replace conventional interpolation techniques for comb-type pilot-added channel estimation in OFDM systems without
inter-carrier interference. The performance evaluation of the analytic interpolator is performed both on the basis of theory
and through simulation, and the results from both the analyses are found to be in good agreement. The simulation results show
that the proposed method can effectively mitigate the ill-influences of limitations on the number and position of the pilot
subcarriers and that it also outperforms the cubic spline interpolation and linear interpolation, especially for short or
nonequidistant pilot patterns. 相似文献
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在Mobile WiMAX OFDMA系统下,研究了线性插值、二阶多项式插值和三次样条插值等几种经典的内插拟合的信道估计方法,仿真发现它们不能很好地支持高速移动性,基于分段线性插值算法提出了一种改进方法。在ITUVA60和Va120信道环境下,对这几种内插算法的误比特率和均方误差性能进行了仿真。仿真结果证明,在高速移动环境下,提出的改进方法要比其他几种算法的性能要好。 相似文献
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On the comparison of interpolation methods 总被引:23,自引:0,他引:23
Maeland E 《IEEE transactions on medical imaging》1988,7(3):213-217
A study of different cubic interpolation kernels in the frequency domain is presented that reveals novel aspects of both cubic spline and cubic convolution interpolation. The kernel used in cubic convolution is of finite support and depends on a parameter to be chosen at will. At the Nyquist frequency, the spectrum attains a value that is independent of this parameter. Exactly the same value is found at the Nyquist frequency in the cubic spline interpolation. If a strictly positive interpolation kernel is of importance in applications, cubic convolution with the parameter value zero is recommended. 相似文献
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在卫星移动多媒体广播系统中,由于多普勒频移及多径影响,信道是时变的,需要估计出信道的时域或频域响应来消除时变信道对传输信号的影响。针对GY/T 220.1-2006标准的导频插入图案,提出了一种基于LS估计准则、在时间轴方向二维线性内插、频域轴方向变换域内插的信道估计算法。仿真结果表明,在不同多径信道的情况下,随着信噪比的增加,该算法的性能均优于最近插值、线性插值和低通滤波插值算法。该算法计算复杂度较spline插值和cubic插值低,适于硬件实现。 相似文献
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在分析了样条函数插值基础上,提出最平坦的三次样条插值问题,并提出了利用粒子群优化算法解决该问题。最后给出了一个实例。 相似文献
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在分析了基本样条函数插值基础上,对传统的三次样条函数作了推广。研究了任意一个插值点一阶导数和二阶导数的边界条件的样条函数解法。最后通过实例,说明了该计算方法。 相似文献
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在通信工程实践中,经常会遇到离散测量数据的拟合问题,即用已知的有限样本估计一些缺失的未知样本,这时就需要借助插值运算.通过对三次样条插值算法进行研究,将其应用至自由空间损耗计算、馈线插入损耗估计、相关干涉测向3个方面,并通过仿真验证三次样条插值算法在通信工程应用中的有效性. 相似文献
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Channel estimation techniques based on pilot arrangement in OFDM systems 总被引:15,自引:0,他引:15
《Broadcasting, IEEE Transactions on》2002,48(3):223-229
Channel estimation techniques for OFDM systems based on a pilot arrangement are investigated. Channel estimation based on a comb type pilot arrangement is studied through different algorithms for both estimating the channel at pilot frequencies and interpolating the channel. Channel estimation at pilot frequencies is based on LS and LMS methods while channel interpolation is done using linear interpolation, second order interpolation, low-pass interpolation, spline cubic interpolation, and time domain interpolation. Time-domain interpolation is obtained by passing to the time domain by means of IDFT (inverse discrete Fourier transform), zero padding and going back to the frequency domain by DFT (discrete Fourier transform). In addition, channel estimation based on a block type pilot arrangement is performed by sending pilots in every sub-channel and using this estimation for a specific number of following symbols. We have also implemented a decision feedback equalizer for all sub-channels followed by periodic block-type pilots. We have compared the performances of all schemes by measuring bit error rates with 16QAM, QPSK, DQPSK and BPSK as modulation schemes, and multipath Rayleigh fading and AR based fading channels as channel models. 相似文献