查询词典 modulation

The most important of the most commonly used analog modulation is the sine wave as a carrier perspective modulation and amplitude modulation.

最常用最重要的模拟调制方式是用正弦波作为载波的幅度调制和角度调制。

Then three candidate modulation schemes exploiting spatial dimensions are proposed. At last, the three modulation schemes are compared by power efficiency and bandwidth efficiency. It shows that spatial quadrature amplitude modulation scheme is appropriate for long distance wireless optical communications for its high bandwidth efficiency and spatial circular symmetry.

参照传统时域信号设计方案，提出了三种空间调制信号具体设计方案，并从带宽效率和功率效率两性能上进行了比较，结果表明正交幅度调制具有带宽效率高、功率效率低的特点，而且采用的信号点越多其带宽效率就越高，另外其空间信号图案还具有圆对称性，因此非常适合在空间带宽有限的远距离无线光通信中使用。

This article first described frequency changer's development process, proposed the PWM velocity modulation method's superiority, had pointed out the future PWM velocity modulation method's prospects for development, the spot will leave has studied the PWM velocity modulation method the significance.

本文首先描述了变频器的发展历程，提出了PWM调速方法的优势，指出了未来PWM调速方法的发展前景，点出了研究PWM调速方法的意义。

The modulation function can be calculated by Fourier transform, filtering and inverse Fourier transform. The value of modulation function in areas of local shadow and abrupt discontinuities is lower than that in other parts. So modulation is a useful threshold to determine the quality of carrier stripe.

针对这种情况，本论文提出了通过傅立叶变换得到变形条纹图像的调制度函数，设置调制度函数阈值判断条纹质量的优劣，低于阈值的部分认为是不连续、阴影或陡峭区域，使用模板覆盖。

In the thesis, the space vector modulation of MC can be synthesized by fictitious rectifier and fictitious inverter. Two space vector control strategies of MC, which combines output line voltage space vector modulation and input phase current space vector modulation, is adopted.

本文采用输出线电压空间矢量调制和输入相电流空间矢量调制相结合的双空间矢量调制策略，对虚拟整流器和虚拟逆变器的空间矢量分别进行了分析，然后将二者综合得到矩阵变换器的调制方法。

"There are two different modulation methods commonly used to do this: pulse-code modulation, which is widely used for transmission in common-carrier communications; and delta modulation, which is finding broad application in military communications."

完成这一转换通常有两种调制方法：脉码调制，这种调制方法广泛用于普通通信传输中；增量调制，这种调制方法在军事通信中使用较多。

Multicarrier modulation in data transmission is discussed in the fourth chapter. The performance of MCM and single tone modulation over twisted pairs is compared. Discrete multitone modulation is used in ADSL system. A new variable constellation TCM method is proposed, It can adapt to the subchannel capacity automatically. The simulation results prove that this method is quite effective.

第四章讨论了多载波调制技术在数据传输中的应用，针对市话信道的具体传输环境，比较了单载波调制与多载波调制的性能；针对ADSL传输的目标，采用离散多频音DMT技术，独立提出一种新的星座图变化的格状码方案VCTCM，能动态地适应不同子信道的传输能力，给出的计算机仿真结果表明该方案有较好的效果。

The composition voltage, the electric current double closed loop voltage-stabilized source, used the integrated phase shifting crystal thyratron module to do for the electrical energy transformation component, in detail has calculated the rectification main circuit main component parameter; In the pulse-duration modulation part, used the special-purpose integrated circuit to realize the frequency modulation to adjust the pressure, did take IGBT as the power transformation component, realized the output voltage frequency modulation to adjust the pressure, and has calculated the related parameter.

在调压稳压电压源设计中采用二阶工程设计法设计了电压和电流调节器，组成电压、电流双闭环稳压电源，采用集成移相晶闸管模块做为电能变换器件，详细计算了整流主电路主要器件的参数；在脉宽调制部分，采用专用集成电路实现了调频调压，以 IGBT 做为功率变换器件，实现了输出电压的调频调压，并计算了有关参数。

The amount of pulse width modulation pulse generators of the proposed modulation strategy is only the half of that of the traditional modulation strategy, which is of significant theoretical and practical value for the digital implementation of cascade multilevel converter.

该策略较传统的载波相移SPWM可以节省一半的脉宽调制(pulse width modulation，PWM)脉冲发生器，对级联型多电平逆变器的数字化实现有重要的理论和实用价值。

Switching Power Supply has three kinds of control circuits: Pulse Width Modulation, Pulse Frequency Modulation, Pulse Width and Frequency Modulation.

开关电源有三种控制方式：脉冲宽度调制、脉冲频率调制、脉冲宽度频率调制。

Through comparing with the results by simulation to study the effects of theprojectile"s final velocity, the angle of rotation and the ballistic trajectory"s migration withdifferent projectile"s rotating speeds, different target"s moving speeds and differentpenetration angles.

通过比较数值模拟的结果来研究不同弹头转速、目标速度、侵彻角对侵彻过程中弹头最终速度、翻转角度和弹道偏移的影响。

I love stationery and all the accoutrement of writing.

我爱文具以及所有的书写的工具装备。