查询词典 modulation

The general analytic expression of the space vector modulation wave was induced and the continuous and discontinuous modulation mode were unified by the analytic expression.

文中归纳出空间矢量调制调制波的通用解析表达式，并由此将连续调制和不连续调制统一起来。

First we depicted one theoretical model of LCoS device, and then working modes of LCoS used as phase-only SLM were selected and optimized by varied the twist angle of liquid crystals and polarized angle due to parameter space method, two working modes, which are suitable to apply LCoS as phase-only SLM, were found, that is (0°, 0°) and (0°, 52°). Theoretical study also showed that the (0°,52°) could be used as a compound device, it behaved property of intensity modulation if a working point was selected appropriately and it behaved property of phase modulation when another wording point was selected. At the same time, this two working modes were studied detailed by extended Jones matrix method.

首先建立了LCoS器件的理论模型，并采用参数空间的方法通过改变液晶的扭曲角度和偏振片的起偏角度选择和优化了LCoS器件用作相位调制的合适的工作模式，找到了两种比较合适的作为相位调制的工作模式----(0°，0°)和(0°，52°)配置。

Based on surveying the development of variable frequency power supply and analyzing its development tendency, and considering the practical features of the assignment, the conversion system is designed as follows: it selects the 3-phase Pulse Width Modulation Engine SA4828 as the PWM control signals generator; it chooses the single-chip-computer PIC16F877 as the microcontroller, which integrated the A/D modulation, which cuts down the complexity of the hardware system and strengthens the dependability of the system.

在论述和分析了变频电源及其控制技术发展的概况和趋势的基础上，结合本课题任务的实际要求，设计了一套中小功率的逆变电源。系统中PWM控制信号采用专用集成芯片SA4828生成，减轻了控制器的工作量也提高了系统的可靠性。控制器选用集成了A/D转换器的单片机，使得系统的硬件复杂性降低，提高了可靠性。

Simulation results show that our algorithm enforces the adaptability of differential space-frequency modulation to the time delay expansion.Finally, we give our work to reduce the complexity of multiple symbol differential sphere decoding in differential space-time modulation. Through the modification of the enumeration strategy of the search tree in sphere decoding, we significantly reduce the complexity of detection at the expense of little loss on performance.

理论分析和仿真结果都验证了这种检测算法对长信道时延的适应能力论文最后还对差分空时调制中的多符号检测算法进行了研究，提出了一种降低差分空时调制系统中多符号差分球形译码算法复杂度的方法，通过改进球形译码中搜索树的排序策略，使得系统在牺牲较少性能的基础上大大降低了算法实现的复杂度。

Theoretical analysis of and experiments on the fundamentals, efficiency, cross-modulation, inter-modulation and spectrum analysis of multiple-frequency acousto-optic Bragg diffraction are made and its application in laser high-speed printer illustrated.

本文对多频声光布喇格衍射的原理、效率、交叉调制、互调制、频谱分析等进行理论分析和实验研究，并阐明其在激光高速印字机中的应用。

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。

The results show the temporal pulse shape modulation is affected by the broadening factor and the delay time, as spectrum modulation is only affected by the delay time, and the intensity factor changes similarly with the cosine function of the phase factor.

研究结果表明，时间调制与基元脉冲的展宽量及相邻脉冲之间的延迟时间有关，光谱调制只与相邻脉冲之间的延迟时间有关，而强度的演化则与相位因子的余弦函数演化具有一定的相似性。

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。

Pachomius manual labour was organized as an essential part of the monastic life; and since it is a principle of the monks as distinguished from the mendicants, that the body shall be self-supporting, external work of one sort or another has been an inevitable part of the life ever since.

根据圣pachomius体力劳动组织作为一个重要组成部分寺院生活；以来，这是一个原则的和尚，作为有别于乞丐，该机构应自支撑，对外工作的这种或那种已一个必然的一部分，生活至今。

In order to study the effects of parametrical rolling on the ship movement and tilts, in allusion to ship's navigating in regular following waves, the equation of ship rolling motion is transformed into normal Mathieu equation by proper variable replacement when strong parametrical excitation in restoring moment varied according to sine or cosine wave.

为研究参数横摇对船舶运动和倾覆的影响，通过对船在规则波上随浪航行时，恢复力矩中出现的1个以正余弦规律变化的强参数激励项进行适当的变量置换，将船舶的横摇运动方程转换成标准形式的Mathieu方程。