共查询到16条相似文献,搜索用时 171 毫秒
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本文首先讨论并分析了各种插值DFT(离散傅里叶变换)算法,然后提出了一种实正弦信号的快速插值频率估计方法。该方法只需 3个DFT变换系数的实部构造频率修正项,计算量低,具有精度高、测频速率快的特点。计算机模拟和FPGA仿真均证实了该方法的有效性。 相似文献
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本文提出了一种改进的DFT信道估计算法,首先将频域信道估计转换到时域,然后将时域中循环前缀长度之外的信道估计值置零。在此基础上,改进的算法要求对循环前缀之内,也就是n≤LG-1的信道估计值做进一步的处理,以便进一步消除噪声的干扰。通过计算机仿真验证了改进的DFT算法优于原算法。 相似文献
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提出了一种基于重叠变换的自适应干扰抑制算法,利用调制重叠变换(MLT)把接收机信号映射到变换域进行抗干扰处理,它可以有效地把干扰能量集中在有限的变换域子带(Transform Bins)中,与基于DFT、DCT等块变换相比有更好的滤波效果。由于可以使用基于重叠变换的快速算法,因此它结构简单,节省计算量。仿真结果表明,基于MLT的变换域处理方案可以有效地改善系统性能。 相似文献
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本文提出了一种简单而实用的利用短时DFT(ST-DFT)分析实现全数字2DPSK接收机的解调算法。该算法对由多谱勒效应引起的时变频率漂移具有鲁棒性。由于该算法是通过检测在载频处的瞬时能量谱的跳变来实现2DPSK信号的解调,所以该算法不需要进行专门的载波相位恢复、符号定时,且具有较好的抗噪性能,实现起来简单。 相似文献
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是一种全新的基于群体智能的后启发式计算技术,具有高教的计算性能和优良的全局搜索能力.本文描述了0/1背包问题的数学模型,分析混合蛙跳算法基本流程,改进混合蛙跳算法,并将该算法应用到0/1背包问题的求解,形成了基于混合蛙跳算法的背包问题求解算法. 相似文献
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为分析离散傅里叶变换(DFT)与离散正弦变换(DST)对单载波频分多址(SC-FDMA)系统某些性
能的影响,提出了一种基于离散正弦变换的单载波频分多址系统。给出了基于DST的SC
-FDMA系统的结构框图,接着重点推导和分析了DST IFDMA和DST LFDMA信号的时域表达式,
最后讨论了系统的峰值平均功率比(PAPR)和不同脉冲成形滤波器的冲激响应。仿真结果表明
,基于DST的SC-FDMA系统比传统的基于DFT 的SC-FDMA系统和正交频分多址接入(OFDMA)系
统有更好的比特误码率。此外,DST SC-FDMA信号的PAPR性能接近于DFT SC-FDMA且优于OF
DMA。 相似文献
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提出了一种适用于OFDM系统的最小均方(LMS)滤波的信道估计算法,对发送序列中导频位置的信道响应进行LMS滤波,进一步得出所有子载波上的信道响应。仿真结果表明,该方法同基于离散傅里叶变换(DFT)的信道估计算法相比,改善了估计的均方误差(MSE)和误码率(BER)性能。 相似文献
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This paper examines the variables influencing a consumer's satisfaction and continuous use of a multichannel retailer's mobile application. Drawing upon the Expectation Confirmation Model for Information Technologies, post-adoption literature, and consumer behavior literature, we assess pertinent factors on the continuous usage of multichannel retailers' mobile apps. Through a sample of 1009 consumers who retained a retailer's mobile app for more than 6 months and conducting Structural Equation Modelling, the findings illustrate that utilitarian variables (perceived usefulness, ease of use, and personalization), hedonic variables (perceived enjoyment), and a brand-related variable (consumer loyalty intention toward the retailer's brand), play a significant role in influencing continuous usage of multichannel retailers' mobile apps. In contrast to e-commerce research, the study outlines that escapism plays a negative role in both consumer satisfaction and intention to continue to use a multichannel retailer's mobile app. Previous research points to the fact that consumers' retention of retailers' apps is low. This paper contributes to the emerging literature on consumers' continuous use of retailers' mobile apps through enhancing our understanding of technology and non-technology-related variables. 相似文献
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Economic Freedom and Cross‐Border Acquisitions from Emerging Markets into Developed Economies 下载免费PDF全文
Extending the home base perspective by considering investors' parent countries, this study examines the effect of economic freedom (EF) on emerging‐market enterprises' (EMEs) overseas acquisition completion in developed countries. Using a large data set of 5,174 cross‐border acquisition deals from ten major emerging markets (EMs) during 1985–2011, we find that (1) the probability of deal completion is positively associated with the levels of EF of the acquirers' countries, the acquirers' parent and the target; (2) the EF of the countries of acquirers' parents has a substitutive effect on that of the acquirers' countries; (3) the difference of EF between the targets' countries and the countries of acquirers' parents negatively influences deal completion; and (4) the difference of EF between the targets' countries and the acquirers' countries negatively influences deal completion. These findings have important theoretical implications for international business scholars, as well as practical implications for managers and for policymakers of EMEs that are active in foreign direct investment. © 2016 Wiley Periodicals, Inc. 相似文献