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提出了一种应用于TD-SCDMA系统中的快速频率估计算法.这种算法利用训练序列估计信道冲击响应,恢复不受信道干扰的发送信号;然后利用最大似然估计算法和二分数值估计算法,估计出较为准确的频率偏移值.仿真表明,该算法比常用的频率估计算法具有更低的复杂度,而且在高斯白噪(AWGN)和多径衰落环境下,均能够对TD-SCDMA系统中的频率偏移获得较为准确的估计结果. 相似文献
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介绍了机车综合无线通信设备CIR在铁路和谐号大功率机车上的应用情况,重点分析了CIR常见故障产生的原因及处理方法,并预测了CIR设备在和谐号大功率机车上未来的发展趋势。 相似文献
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马保国 《武汉理工大学学报(材料科学英文版)》2011,26(6):1211-1214
The property of reclaimed asphalt pavement(RAP) mixture will be affected mainly by composition of old asphalt/soil and cement
content in CIR system. We studied the relationship between A/S and cementitious materials. It showed that if there was no
soil in RAP, the unconfined compressive strength was only from 0.18 MPa to 1.07 MPa even if adding cement was from 2% to 6%,
and RAP samples collapsed during conserving in water. The optimum water content rose from 6.5% to 11% with the declining of
A/S from S=0 to A/S=1/5. Five RAP samples all got the maximum compressive strength when A/S=5/5, and the maximum compressive
strength of the samples adding 6% cement was 3.17 MPa. It showed that the capacity of RAP was not only affected by A/S, but
also by the content of cement. The dynamic modulus of RAP will increase with the rise of loading frequency and decrease with
the temperature rising. SEM test showed that C-S-H interlacing formed the netted structure, and it enwrapped the aggregate
and improved the strength of RAP. 相似文献
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为了提高CIR利率期限结构模型中的状态估计精度,建立了该问题的离散非线性滤波模型,采用高斯粒子滤波法进行状态近似最优估计.相对于文献中普遍采用的扩展卡尔曼滤波方法,高斯粒子滤波法避免了线性近似带来的误差,利用基于重要性采样得到的高斯分布来近似状态变量的后验分布,具有更强的状态估计能力.仿真实验比较了高斯粒子滤波和扩展卡... 相似文献
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分析了CDMA系统中不同的信道参数下,基于功率平衡与功载扰比平衡的功率控制方案对系统性能的影响。仿直结果指出,采用基于载扰比平衡的功率控制方案、可以使系统的上行与下行链路获得最佳的性能。 相似文献
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Capacity enhancement and interference performance are among the most important issues in the 2nd and 3rd generation cellular networks planning. The main objective of the planning process is to reach a tradeoff between the quality and the capacity of the network. In this paper, we study and compare the CIR and spectral efficiency of different cellular reuse patterns. We also establish the exact analytical PDF expression of CIR assuming one interferer in the serving cell, we then generalize this expression to many interferer tiers. Shadowing effect is also carefully considered in the CIR distribution extension. Moreover, numerical computations are performed to estimate spectral efficiency values for the different patterns studied. Some simulations are also developed to give the comparison a concrete and a practical aspect. A reuse partitioning (RP) capacity scheme is used to serve as the basis of the study. In particular, RP sub‐cells' sizes and number of partitions are optimized in order to maximize the traffic capacity parameterized by spectral and trunking efficiency while involving the financial cost. The efficiency/cost comparison is among the main novel issues contributed by the paper. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献