查询词典 delay modulation

Experiments shows that it can detect the carrier frequency and the low frequency of modulation signal as expected, the resolution of the carrier frequency is 0.3Hz,the detecting error is within ±0.5Hz, and the resolution of the low modulation frequency is 0.07Hz, the detecting error is within ±0.05Hz.

实验结果表明该检测仪能很好地检测出信号的载频和信号的低频调制信息，其中信号载频的分辨率为0.3Hz，误差范围在±0.5Hz 以内，低频信息的分辨率可达0.07Hz，信号的误差在±0.05Hz。

In this paper,a design method of two dimensional Linear Phase Nearly Perfect Reconstruction filter banks based on a new class of cosine modulation systems is presented,which can be described as follow: firstly,the Parks-McClellan algorithm is adopted for designing the prototype filter,then by employing cosine modulation,a series of analysis and synthesis filters can be obtained,accordingly a one-dimensional LP-NPR filter banks can be constructed;Secondly,cascading two one-dimensional LP-NPR filter banks in the form of tree structure and using the unimodular transformation,a two dimensional nonseparable LP-NPR filter banks can be obtained.

提出了一种基于一类新余弦调制系统的二维线性相位-近似完全重构滤波器组的设计方法，设计过程分为两个步骤：首先采用Parks-McClellan算法来计原型滤波器，再经过余弦调制能到一系列的线性相位分析和综合滤波器，从而可以构造一维LP-NPR滤波器组；然后利用树状结构来结合两个一维LP-NPR滤波器组，并运用单位模变换，可以得到二维不可分离LP-NPR滤波器组。

And the cross correlation function is approximately zero, which makes them suppress the disturbances due to the other users. After describing some basic knowledge of chaotic theory in chapter 2, we interview and classify the applications of chaos in communications including chaos secure communication, chaotic spreading codes for multi-user access in spreading spectrum system and chaotic modulation and demodulation in chapter 3. FM-DCSK system with non-coherent demodulation offers the best performance in chaotic modulation schemes.

在混沌调制方案中， FM-DCSK调制是一种极具竞争力的混沌调制方式，它克服了CSK、COOK、DCSK解调中存在的估计问题的缺点，在无线信道的传输过程中，可以很好的抑制噪声干扰与多径衰落，并且能获得非常优越的解调性能，加上混沌信号本身优越的保密性能，该调制方式在未来的无线通信领域存在着巨大的潜在优势。

The main method of modulation is decompound and combiniton, the system and products of modulation consist of standard modules.

模块化的主要方法是系统的分解和组合，模块化的产品或系统是由标准的模块组成的。

By means of a linear array CCD lightintensity distribution measuring system, via the variation of the frequency and the power of ultrasonic wave, the direction control and the intensity modulation for the laser beam can be carried out. The relation curve between acoustooptic deflexion and modulation measurement is given.

在实验中，应用线阵CCD光强分布测量仪等，通过改变超声波的频率和功率，分别实现了对激光束方向的控制和强度的调制；定量给出了声光偏转量的关系曲线和声光调制测量的关系曲线。

A mathematical upper bound of the modulation index for nonlinear distortionless transmission of wireless signal over fiber was derived according to the speciality of analog optical link modulation process.

3通过具体分析马赫—曾德调制器非线性失真的原因和所导致的影响，根据模拟信号光纤传输链路光载波信号的调制特点，推导出无线光传输链路进行信号无失真传输的光调制指数上限。

The framework of digital frequency modulation exciter is proposed, and the realization scheme of stereo signal composition and frequency modulation is studied.

提出了数字调频激励器的总体框架，研究了立体声信号合成和频率调制的数字实现方案。

First, mathematic description of FOG's modulation signal was analyzed, and then three methods for producing modulation signal with adjustable amplitude were discussed, which are direct wave table method, multiplicative amplitude adjusting method and two-level wave table method. Their advantage and disadvantage were analyzed.

首先对光纤陀螺调制信号的数学描述进行了分析，在此基础上提出了三种幅度可调调制信号的产生方法，即直接波表法、乘法调幅法、两级波表法，并分析了三种方法各自的优缺点。

First,mathematic description of FOG's modulation signal was analyzed,and then three methods for producing modulation signal with adjustable amplitude were discussed,which are direct wave table method,multiplicative amplitude adjusting method and two-level wave table method.

首先对光纤陀螺调制信号的数学描述进行了分析，在此基础上提出了三种幅度可调调制信号的产生方法，即直接波表法、乘法调幅法、两级波表法，并分析了三种方法各自的优缺点。

I introduced in the paper one kind of VVVF elevator control system, I has used the closed loop velocity modulation regarding the elevator velocity modulation system, and has carried on the detailed design separately to the hardware electric circuit main part,including PLC control section,frequency changer,main circuit and gate and so on.

在论文中我介绍了一种VVVF的电梯控制系统，对于电梯的调速系统我采用了闭环调速，并对硬件电路的主要部分分别进行了详细设计，包括PLC控制部分，变频器，主电路和门电路等。

Objective:To explore the feasibility of laparoscopy in diagnosing and treating of abdominal diseases.

目的：探讨腹腔镜用以诊断腹部外科疾病及选择治疗方案的可行性。

The lifetime of nylon 1010 and nylon 1010/POSS composites decreased with increasing temperature.

热重-红外联用分析表明尼龙1010在氮气气氛下的降解产物主要为小分子的低聚物，POSS并不改变尼龙1010降解产物的组成。