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基于导频的OFDM信道估计方法及分析 总被引:3,自引:1,他引:2
对OFDM系统中基于导频的信道估值器进行了比较分析,分析了DVB-T系统中导频的分布,在DVB-T系统基础上结合最大似然准则和最小均方误差准则,提出了信道估计的方法,并在Reyleigh信道模型下,运用Matlab实现仿真. 相似文献
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未来无线移动通信需要高速率和高质量的数据传输能力。OFDM技术具有高速数据传输能力和较高的频谱利用率成为下一代无线通信的关键技术[1],而信道估计又是决定OFDM通信质量的关键技术。本文对多载波正交频分复用(OFDM)系统最常见的两种信道估计算法,即最小平方算法和最小均方误差算法进行介绍,并在MATLAB环境下仿真比较了两张算法。仿真结果表明MMSE算法的误码率优于LS算法,当信噪比越低时,MMSE的优越性越明显。 相似文献
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对光正交频分复用(OFDM)系统中传统导频的帧同步误差估计算法与性能进行了深入研究,针对其不足提出一种基于块状导频的由帧同步错误引入的信号幅度和相位畸变估计的新算法。仿真结果表明,在同一导频开销的条件下,对比传统块状导频与梳状导频的补偿算法,所提出的新进算法对应误码率(BER)曲线更接近无同步错误的理想BER曲线,在相同BER下,与理想曲线的信噪比(SNR)相差最大不超过0.2dB。所以,本文新算法能有效地提升性能,实现较为理想的帧同步错误的导频补偿,更适合用于纠正由帧同步误差引入的幅度和相位误差。 相似文献
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本文提出了一种正交频分复用(OFDM)系统的频率同步方案。该方案包含一个细同步算法和一个粗同步算法。细同步算法是对MOOSE算法的改进,使其频率捕获范围扩大一倍;粗同步算法通过对特殊的长训练序列进行频域相关运算,来估计大范围的频率偏移,它与改进的细同步算法合,能够纠正达到半个系统带宽的频偏。仿真表明这是一种准确而可靠的频率同步方案。 相似文献
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正交频分复用(0FDM)是一种高效的数字传输技术,因其较高的频带利用率以及抗多径衰落的性能,被视为下一代无线通信的核心技术。信道估计是视线OFDM系统的关键技术之一。主要研究了OFDM无线通信系统中基于导频的信息估计算法——LS算法,MMSE算法以及改进的LS算法,并通过仿真算法的最小均方误差性能和误码率特性证明了改进的LS算法要优于LS算法。 相似文献
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最大似然时偏估计算法对OFDM系统同步性能的改善 总被引:3,自引:3,他引:3
文章提出一种新的OFDM系统中的最大似然时偏估计算法,该算法在AWGN信道和多径衰落信道两种环境下与H.Minn的算法基于估计的均方误差进行了性能比较,通过比较,得出该算法不仅在高信噪比的情况下.而且在多径衰落环境下仍能保证较高的估计精度和较低的运算复杂度。 相似文献
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OFDM系统中的信道估计算法比较 总被引:2,自引:0,他引:2
研究了OFDM系统中基于LS、MMSE及SVD的信道估计算法,并对其进行了性能分析和比较.通过SVD降低了运算复杂度,简化了MMSE算法,且性能良好. 相似文献
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Fang Zhi Xiao Wan'ang Shi Yin 《电子科学学刊(英文版)》2008,25(1):1-6
A new fine carrier frequency offset estimation algorithm in Orthogonal Frequency Division Multiplexing (OFDM) system is proposed. The correlation item is the training sequence instead of the received signal in the new algorithm. Simulation results show that the performance of the new algorithm is 4dB-9dB better than that of Schmidl's algorithm. Coarse frequency offset estimation is also discussed in this paper, which is the improvement of Zhang's method. The estimation range using the improvement method is twice as that using the Zhang's method. Based on the hardware of the receiver and the improved algorithm, a method using Fast Fourier Transform (FFT) is proposed to implement the coarse frequency estimation. The chip area of OFDM system can be reduced by using the proposed method. 相似文献
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A pilot-aided Orthogonal Frequency Division Multiplexing (OFDM) frequency offset estimator designed for satellite communication system is proposed in the paper. The estimator focuses on the acquisition of the integer part of carrier frequency offset and the acquisition range is as large as the whole signal bandwidth. Making full use of the phase difference between received pilot and local referential pilot, a fast estimation is obtained. Compared with existing method, our method can also work well even in SNR as low as 0dB. Simulations verify the good performance of our method. 相似文献
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Li Jun Liao Guisheng Wu Yuntao 《电子科学学刊(英文版)》2006,23(1):121-123
Most of the blind Orthogonal Frequency Division Multiplexing (OFDM) Carrier Frequency Offset (CFO) estimators necessitate large number of samples to ensure the estimation accuracy. However, the number of samples can not be selected too large because of the carrier offset drift. In this letter, a new closed form algorithm for blind OFDM CFO estimation in frequency-selective channel is proposed. This method utilizes the propagator obtained from data matrix and the diagonal loading technique, thus it has better performance even only using one or two OFDM blocks. Furthermore, the range of the CFO estimation which can be handled is overall transmission spectral. Simulation results confirm its effectiveness. 相似文献
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提出了一种改进的基于训练符号的频偏估计方法.该方法通过综合利用训练符号和循环前缀的信息得到时域的细频偏估计,通过峰值检测得到频域的粗频偏估计.仿真结果表明,在多径衰落信道下,在频偏估计范围达到整个信号带宽的同时,本算法的估计精度也有了明显的提高,并且当信噪比达到12dB时,可以使剩余频偏限制在子载波间隔的2%以内. 相似文献