查询词典 investigates

The paper investigates both block-type pilot linear minimum mean square error algorithm and IEEE802.16 OFDM channel estimation analysis. Simulation results confirm the block-type pilot structure is more suitable for IEEE802.16 system. An optimal pilot setting algorithm, based on space frequency domain, is explored and the pilot chart is presented. The proposed algorithm finds its application in MIMO-OFDM. Simulation results show the algorithm presents a good approximation to the perfect channel state information curve, with about 2dB difference in SNR. The simulation results also demonstrate the algorithm achieves fairly high stability in the environment of fast fading, performance of the proposed algorithm is better that of pilot training channel estimation.3. Taking into account the characteristics of IEEE802.16 OFDM system, OFDM system simulation platform is constructed in Matlab, exploiting simulink as a tool. OFDM modulation and demodulation simulation system are configured on LabVIEW platform. All the system signal processing is simulated, including defining system parameters, designing modulation model, and verifying all the proposed algorithms under different environments, such as white Gaussian noise, multi-path fading, with or without guard interval etc. Bit error performance is evaluated. The research provides valid theoretical basis for practical OFDM system performance evaluation.4. Taking advantage of software radio, the paper designs a hardware platform with both 256-IFFT/FFT and 512-IFFT/FFT OFDM schemes co-existing in one platform. You can predetermine one from the two schemes to carry out almost the same model function with different system performance and parameter setting.5. Referring to IEEE802.16 standard, the paper proposes a design method for generating signals and frames suitable for laboratory investigations implemented in laboratory environment.6. Based on 6701evm digital evaluation card, combined with analogy front-end, the paper designs a DSP software model to deal with baseband signal processing. An overall OFDM scheme, with modulation and demodulation function, is accomplished.

讨论分析了MIMO-OFDM中一种基于空频域的最优导频设置算法，给出了导频图案，通过仿真实验表明，该算法与理想的信道状态信息曲线非常接近，信噪比差距约在2dB左右，并且在快衰落条件下具有较好的稳定性，其性能要优于基于前导训练的信道估计方法。3、根据IEEE802.16OFDM系统特点，论文分别在Matlab中应用Simulink工具构建OFDM系统仿真平台、在LabVIEW平台上实现了OFDM调制解调仿真系统，模拟了整个系统的信号流程，进行了OFDM仿真系统参数的选择和调制模块的仿真设计、论证各算法性能，并根据各种不同的条件：例如高斯噪声、多径衰落、有无保护间隔等，对系统的误码特性进行了评估，为正确评价实际OFDM系统的性能提供了有效的理论依据。4、论文以软件无线电思想作为指导，提出了以256点IFFT／FFT为核心和以512点IFFT／FFT为核心的两种OFDM算法模式并存于同一个硬件平台、且可预选的方案，它们在参数选取和性能指标上有所差异，均实现了相似的模块和功能。5、论文参考IEEE 802.16无线网络标准的参数设置，针对本设计系统的应用环境和系统硬件的性能速率，提出了一种应用于实验室环境的信号结构、帧格式等参数设计。6、论文基于TI公司的6701evm数字评估板卡，结合模拟前端搭建数字中频平台，设计了基带处理的DSP软件模块并进行系统调试，基本实现了一套完整的OFDM调制解调方案。

The Cult of iPod includes the exclusive back story of the iPod's development; looks at the many ways iPod's users pay homage to their devices; and investigates the quirkier aspects of iPod culture, such as iPod-jacking (strangers plugging into each other's iPods to discover new music) as well as the growing legions of MP3Js (regular folks who use their iPods to become DJs).

本書涵蓋了iPod 的獨家幕後發展史；iPod迷是如何狂熱，描寫了包括iPod-jacking（利用iPod共享音樂的陌生人）和其他快速升級的MP3J（運用iPod而變成像DJ般的人），一探iPod帶來文化上的衝擊與演變。

The dissertation investigates the multilane-to-uniline problem in order to solve the theory problem and technique problem of feeding high speed palletizer with several production lines. The harmony equation of the problem is established with the method of movement tracing according to the thought of unit accumulation and free bumping of materials from different lines. For the random of unit materials forming, a strategy of key assignment is put forward to avoid the bump of materials from different lines.

为了解决采用多条供料线向高速码垛机供料以充分利用高速码垛机的处理能力的理论问题和技术问题，本文从一般的角度研究了多线合一问题，根据料股缓冲的思想和无供料干涉的原则，利用运动追踪的方法建立了多线合一问题的协调方程，由此建立了结构参数之间的相互制约关系，为结构参数的制定提供了理论依据，在随机供料的情况下，由于各线料股的形成具有随机性，为了避免各线之间的干涉，本文提出了一种钥匙分配策略很好地解决了这一问题。

This review investigates the factors contributed to build up the capsular bend formation to help the oculists understanding PCO prevention and cure.

视将对目前正在进行的关于囊袋弯曲结构对后囊混浊影响的研究的一些进展进行综述，并通过探索一些有助于建立囊袋弯曲的因素来帮助眼科医生了解PCO防治的进展。

This paper pays more attention to investigate the affect and value of the dialogues in The Castle, which include the narrative technique, plot, content, and the integrated aesthetic meaning. This paper also investigates the affect and value of the dialogues in other novelettes and short stories of Kafka. So as to form a deep comprehension of the style in Kafka works.

本文将着重考察&对话&对于小说《城堡》的叙事、情节、内容和美学意蕴的作用和价值，兼及卡夫卡的部分中短篇小说中的对话的作用和价值，从而形成对于卡夫卡小说整体风格的深入理解。

Based on experience gained by predecessors, the author re-investigates in flood front zone the high-suspended-sediment-concentration phenomenon found to be in relation with the existence of high current speed pulse of which one possible semi -quantitative mechanism is proposed.

在前人工作的基础上，对潮锋带高含沙量进行了重新考察，发现这种高含沙量现象的出现与潮锋带前缘存在较大流速有关，并提出了相应的半定量的形成机制。

This dissertation mainly investigates TI worm gearing based on meshing theory and optimal design.

本文从啮合理论和优化设计两个方面对 TI 蜗杆传动展开了研究。

In recent years, because experiment ability has been the important contents of the college entrance examination ,educators are gradually pay attention to the instruction research of Biological Experiment ability which domestic data is less ,and the data is oppositely more little that about test and investigation into Quasi—teachers' Experiment Teaching Ability of Biology This research investigates and analyzes the upperclassmen' evaluation importance of experiment teaching ability who are in College of Life Science of Shanxi Teachers'University .

实验安全维护能力和指导实验结束后的讨论活动能力是被国外和台湾学术界普遍认为的两项重要能力，在这里却退居较重要能力，这是否是我们大学、中学实验教学缺少实验室安全维护和实验结束后的讨论活动要求的一种真实反应？如果真是这样，那么，最现实、迫切的实验教学改革便需从此处入手了。

This article investigates the effect of short-range interaction of strongly correlated electrons on the Peierls transition of a quasi one-dimensional system.

研究短程强电子关联对Peierls相变的影响。研究结果表明，短程强库仑作用对Peierls相变的影响与电子填充有关。

The Chinese television profession from it that moment which is born in China, experienced take propagandized the attribute as the leading first stage, take creator art work attribute as leading second stage, Enters slowly has occupied the dominant position now by the cultural commodity the third stage, after at present this stage field weight standard is each column weighting the viewing ratio height, But regardless of has various understanding and the discussion to the viewing ratio, also no matter the viewing ratio essence is good or bad, the list from the data analysis starting point, it indeed can reflect and explain very many questions, In view of the fact that the author at the Central Committee Television seventh set of agriculture program " the date of the countryside " the column practical work experience with CCTV Rope Luck Switzerland Investigation Company the data feedback which column each reception of TV investigates to "the date of the countryside", Simultaneously furthermore has to the agricultural dissemination study concrete understanding, this article analyzes emphatically from the television jobholders' angle to this range pole -like viewing ratio data, obtains corresponding fords the agricultural television conversation class program the creation method and to the television medium thorough understanding.

中国电视行业从其在中国诞生的那一刻起，经历了以宣传属性为主导的第一阶段，以创作者艺术作品属性为主导的第二阶段，慢慢进入了现在以文化商品占主导地位的第三阶段，目前这个阶段业界的衡量标准就是各频道各栏目加权后收视率的高低，但是无论对收视率有何种理解和探讨，也不管收视率的本质是好还是坏，单从数据分析的出发点来说，它的确能够反映和说明很多问题，鉴于笔者在中央电视台第七套农业节目《乡约》栏目的实际工作经验和央视索福瑞调查公司对《乡约》栏目各项收视调查的数据反馈，同时更兼有对农业传播学的具体理解，本文着重从电视从业人员的角度对这个标杆式的收视率数据加以分析，得出相应的涉农电视谈话类节目的创作方法和对电视媒介走向的理解。因此本文是建立在对《乡约》栏目的收视率数据分析、受众收视倾向分析以及《乡约》栏目的电视节目创作经验总结基础上所得出的涉农类电视访谈节目的创作规律和理念。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。