设计

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。

In the product design, uses modular, the parametrization 3D computer design system to carry on the modelling design, may personalize has custom-made, the image is lifelike, the effect is direct-viewing; On the production equipment, has provided the precise numerical control machinery, including the numerical control plate cutter, the numerical control knee bend machine, the numerical control key seating machine, the plasma cutter and so on, has the advanced working capacity; In the technical strength, has one batch of collection design, the manufacture, the installment is a body, experienced professionals.

在产品设计上，采用模块化、参数化的3D电脑设计系统进行造型设计，可以个性化定制，形象逼真，效果直观；在生产设备上，配备了精密的数控机械，其中有数控剪板机、数控折弯机、数控开槽机、等离子切割机等，具有先进的加工能力；在技术实力上，拥有一批集设计、制造、安装为一体，经验丰富的专业技术人员。

This article mainly introduced the igniter plug iron casing crowds the pitch diameter working procedure swaging to design the entire process, it has produced the concrete design method and the step.

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Geography homework design should also the body living this principle now, this text front place homework and postposed homework design to do study:Front place homework proper and plain, have a direction type, personal with group cooperation combine together, have to open sex;The classroom homework want to with meticulous care choose while and then placing homework design, innovation design fill diagram homework and expand extension homework outside the lesson, homework outside the lesson also should recreation.

地理作业设计也应体现生本理念，本文就前置作业和后置作业设计做了探讨：前置作业宜浅显、具有导向型、个人与小组合作相结合、具有开放性；而后置作业设计时课堂作业要精心选题、创新设计填图作业、拓展延伸课外作业、课外作业也应休闲。

Geography homework design should also the body living this principle now, this text front place homework and postposed homework design to do study:Front place homework proper and plain, have a direction type, personal with group cooperation combine together, have to open sex;The classroom homework want to with meticulous care choose while and then placing homework design, innovation design fill diagram homework and expand extension homework outside the lesson, homework outside the lesson also should recreation.

郭思乐教授提出的&一切为了学生，高度尊重学生，全面依靠学生&的生本理念，注重培养学生学习的主动性和自主性。地理作业设计也应体现生本理念，本文就前置作业和后置作业设计做了探讨：前置作业宜浅显、具有导向型、个人与小组合作相结合、具有开放性；而后置作业设计时课堂作业要精心选题、创新设计填图作业、拓展延伸课外作业、课外作业也应休闲。

There are many factors to influence the accuracy of laser alignment and target position.

本论文正是针对上述因素，在神光II升级项目靶场分系统的设计中，通过对靶场中关键元器件的优化设计，以提高焦斑性能和激光弹着点控制精度，使其满足系统设计的要求，为项目的顺利实施提供必要的设计参考数据。

Ship virtual reality design is the application of virtual reality techniques in ship design, realizing two stratifications of virtuality. The first is making possible for the ship owner, designers, shipyard and ship classification society to participate in ship design steps to pre-experience the performance of production. Second, it can put the emphasis on manufacture system and carry out effective analysis on its feasibility.

船舶虚拟现实设计是虚拟现实技术在船舶设计中的应用，对船舶设计制造过程实现两个层次的虚拟：一是设计阶段使船东、设计所、船厂、船级社都能够参与，达到预先体验产品性能的目的；二是强调制造系统层次上对生产制造可行性进行有效分析。

CBR principle was applied in design of precision spade punch planter of maize. IDEF0 method was adopted to disassemble design procedure. The nearest-neighbor case retrieval strategy was used to accomplish case retrieval. Then, the retrieved case was modified to meet the needs of the design.

将实例推理技术应用在铲式玉米精密播种机的设计过程中，采用IDEF0法对播种机设计任务进行分解，采用最近邻实例检索策略完成实例检索并根据设计要求进行修整，从而达到设计要求。

Chapter 4: introduces the other part of PAMS, High-performance Low Frequency Differential Signal Generator Based on DAC, discusses the theories and characters of Σ-Δ DAC, and deduces the compensating method of signal generator.

文章首先介绍了并行口方式JTAG控制器的设计原理，然后介绍JTAG控制器接口的硬件设计，最后介绍JTAG指令的时序设计和JTAG控制器的软件设计。

Industry shape-designing is a design method that regards three-dimensional industrial products as described targets,The adoption of the design method need to give oculars image result picture of the product that is designed.

工业造型设计是所有以立体的工业产品为描述对象的设计方法，采用这种设计方法需要给出所设计产品的直观形象效果图。

Chrysanthemum of 10 thousand birthday is lax to edaphic requirement, with the arenaceous qualitative loam with fecund, good drainage had better.

万寿菊对土壤要求不严，以肥沃。排水良好的砂质壤土为好。

He unstepped the mast and furled the sail and tied it.

他拔下桅杆，把帆卷起，系住。