查询词典 block signal

Integrating trellis-coded modulation with threaded algebraic space–time block code, trellis-coded modulation space-time block code is presented, which has the advantage of full-diversity and small detection delay. Based on TCM pre-processing, the minimum distance between different codeword matrixes of the TCMST block code is maximized, so the average bit error rate of the TCMST block code is lower than that of the TAST block code at the same signal noise ratio.

TCMST分组码具有满发送分集度和检测延迟小等优点；由于采用了TCM预处理，使得不同TCMST分组码码字矩阵间的最小距离达到了最大化，因此在相同信噪比情况下，TCMST分组码具有比TAST分组码更低的平均误比特率。

First, argumentation of plan. Second ,introduce hardware, theory of monitor, VGA standard and designing of every block, including synchronized signal generating block ,character rom block, moving block, shift block and comparison block .

首先进行了方案论证，其次介绍硬件，监视器的原理，VGA标准以及各个模块的设计，包括：产生同步信号的模块，字符存储器的模块，移动模块，移位模块，比较模块。

It puts forward the control drawings of split control signal distribution block and cascade control signal distribution block.

并对分程控制、串级分配器的控制回路图连接进行了设计。

If the display indicates a poor signal, adjust your physical location to be clear of obstructions that may block the signal.

如果显示信号弱，调整身体所处的位置，尽量远离一切有可能封锁信号的障碍物。

Signal analysis ; signal concentration and block ; rail transportation

信号分析；信集闭；轨道运输

AC:ac coupling,block the DC signal of input signal only AC signal pass into attenuator.

AC：交流耦合，阻断输入信号的直流信号，只有交流信号通入衰减器。

In order to detect load in tumbling box correctly,the frequency band that could reflect information of mill ball load was obtained from the vibration signal collected from ball mill bearing block.The signal was analyzed by energy method based on wavelet transform,from which the frequency band signal was picked out to show the corresponding coal level in tumbling box.

为了更准确地检测料位，对球磨机轴承座振动加速度信号进行采集，从振动信号中提取了反映料位信息的特征频段，利用小波分析技术对信号进行了能量分析，分离出反映滚筒内存煤量信息的信号，为实现球磨机料位的自动控制提供了理论依据。

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。

Based on an analysis on the present situation and development of three kinds of signal systems (the point system based on interrogator responsor, the quasi moving block system based on digital track circuit and the moving block system based on wireless data transmission) in urban rail transit, some suggestions on the localization of signal system of urban rail transit are put forward.

在分析三种城市轨道交通信号系统制式(基于查询应答器的点式系统、基于数字轨道电路的准移动闭塞和基于无线数据传输的移动闭塞)的现状和发展基础上，对实现我国城市轨道交通信号系统国产化提出建议。

The system consists of phantom, signal source block, power amplifier block, measuring mode setting block, high accuracy amplifier and high speed demodulator.

该系统包括信号源模块，功率放大模块，测量模式设置模块，信号放大模块，同步解调模块。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷