查询词典 digital signal

Because the traditional wireless microphone uses the frequency low silent chain, all is analyzes the radio-frequency signal the intensity, therefore they cannot and need the noise the signal differentiates; In the noisy radio frequency environment (for example digital equipment and so on CD/VCD/LD send out massive overtones) under use, when this launcher signal weak or closure, the silent chain possibly can open suddenly, the receiver can send out the intense demolition noise.

传统无线麦克风因采用频率低的静噪电路，都是分析射频信号的强度，所以它们不能把噪音和需要的信号区分开来；在嘈杂的射频环境(如CD/VCD/LD等数码设备散发出的大量谐波)下使用，在该发射器的信号微弱或关闭时，静噪电路可能会忽然打开，接收机就会发出强烈的爆破噪声。

By using Digital-Trailing-Filter and DSP technology, we got solution of trailing filter for transient signal in frequency-scan test,so as to refine the needed test signal from the deformative and weak signal.

通过采用数字跟踪滤波和DSP处理技术，解决了扫频测量中瞬态信号的跟踪滤波，使仪器能够在畸变的、微弱的信号中提取出需要的测试信号，同时使仪器的测量时间大大缩短。

By time-varying filtering, we realize the signal selectivity and interference suppression, especially for the signals with time-varying power spectrum. It is shown herein that conventional eigenstructure based methods are lower dimensional special case of the time-frequency subspace fitting method. The closed-form array response estimation algorithms for blind source separation in wireless communication is also developed in the dissertation by exploiting the data structure of second-order statistics of the array output in the presence of multipath. The proposed method achieves array response estimation with little constraint on signal property and propagation environment such as scatters or angular spread. Moreover, the array utilized here can be of arbitrary geometry and even uncalibrated. Since the closed-form solution is obtained, no misconvergency may occur and large amount of computation can be saved. The equivalent feed model and corresponding optimization designation are proposed to realize the downlink multi-user selective transmission. By coherent and non-coherent superposition of the electromagnetical field, multiple beams can be formed using a single array, so that each co-channel user signal is transmitted in each beam and will not interfered with each other. The proposed system scheme implements the digital beamforming and the channel allocation in the base band, therefore is suitable for the utilization of the radio software technology. The feasibility and effectiveness of the proposed model are proved by the RF experiment.

在窄带条件下，GSC－SSF方法还可以提高阵列的虚拟孔径，从而提高估计的性能；可以证明，Cyclic DOA 和SC-SSF方法可看作该方法的特例或近似； 3、提出了二维GSC－SSF方法和宽带谱相关DOA矩阵方法，利用信号的循环平稳特性解决了宽带条件下二维 DOA 估计问题，并具有阵元数少、计算量较小的特点； 4、提出了时频子空间拟合和宽带时频DOA估计算法，将联合时频分析的理论和方法引入到阵列信号的空间谱估计研究中，利用时变滤波实现信号选择性测向和干扰抑制，特别适合于谱时变信号；可以证明传统特征结构法可看作是时频子空间拟合方法的特例； 5、提出了多用户环境下阵列响应的估计方法——CARE方法，该方法对信号结构和传播参数（主要是散射源分布与角度散布）的约束较少，适用于各种几何结构的阵列甚至未校准的阵列，能够直接得到阵列响应的闭式解，因此计算量小、稳健性好，不存在收敛问题； 6、提出了针对多用户下行选择性发送的阵列等效激励模型、优化设计方法及其系统实现方案，通过空间场的相干叠加与非相干叠加使得单一阵列能够形成多个波束，并保证各波束内的用户信号各不相同且相互干扰最小；其系统方案具有在基带实现数字波束成形、信道分配并便于软件无线电实现的特点，其有效性已得到外场实测数据的证实。

A digital phase synthesizer is composed of a continuous phase data signal source, an interpolater to generate continuous edge configuration data signals in response with each continuous phase data signal, and a phase modulator to generate ouput clock signal.

一种数字相位合成器包括一个连续相位数据信号源。一个内插器响应每个连续相位数据信号产生连续边沿配置数据信号。一个相位调制器产生具有放置在由连续边沿放置数据信号确定的时间的边沿的输出时钟信号。

The digital frequency source this paper researched uses high integrated DDS chip AD9851 as frequency sources and signal mirac processors AT89C51 as system control center, it can output 10Hz-20MHz signal with high-precision and high stability frequency. The evenness of signal within the range of 10MHz is low to 0.1dB degree, and the smallest step is low to 10Hz frequency.

本课题研究的数字频率源采用高集成度DDS芯片AD9851作为频率源；以单片机AT89C51作为系统的控制中心，实现了10Hz～20MHz的高精度、高稳定度的频率输出。10MHz内信号幅度的平坦度为0.1dB、频率最小步进为10Hz。

Firstly, this paper introduces the principle of digital modulation and digital demodulation simply, as well as the method and the principia of measuring digital modulation signal.

其次，详细讨论了矢量信号分析技术，给出了信号分析的一般模型和一些具体的测量分析方法，总结了矢量信号的测量方案和解调分析的原理框架。

A simple digital device for detecting human balance function is described. The device acquires data of a shaking body of quizzee using a micro sensor for measuring rotator, transforms the data into digital pulse signal, and displays the metrical results through digital display and an audio annunciator.

一种用于人体平衡功能检测的简易式数字检测系统，它通过旋转型传感器采集被测人体的晃动信息，并转化成数字脉冲信号，配合数字显示和声音报警来显示检测结果。

C8051F005 is the control center of the survey meter, the signal is obtained by jaw pressure transformator and current transformator. Direct Digital Frequency Synthetics technology is adopted to automatically adjust the frequency of the actuating signal and avoid the interference of the signal in the ground network.

该检测仪采用C8051F005单片机作为控制处理中心，钳口式电压互感器和电流互感器检测接地电阻信号，运用直接数字频率合成技术自动调整激励信号频率，从而避免地网中干扰信号源的影响。

multi-channel correlators are widely used in traditional pseudo-random code cw radar,which makes the ranging system more complicated.this paper proposes a method of digitalizing the return signal directly and then convoluting the signals on dsp,which can replace multi-channel correlation in analog circuit.but the computation of convolution is too huge for the dsp to fulfill.to solve this problem,this paper analyzes five fast algorithms including fft,and then chooses one according to the characters of prc-cw radars.the digital method and fast algorithm have been verified by simulated signal and real signal.

一种提高空间伪码扩谱测距精度的实用。。。摘要：传统的伪码调相连续波雷达采用多路模拟相关电路实现对回波信号的相关接收，通过多路试探搜索各距离单元的目标，电路复杂。提出的数字化方案，对回波信号直接数字化，利用高速dsp实现数字卷积，可替代多路模拟相关电路。但是直接卷积的运算量过大，dsp无法承受。本文对此进行了研究，分析了包括fft在内的五种快速算法，结合prc-cw雷达的具体情况，确定了一种适于dsp实现的快速卷积算法。仿真和实测数据证实了数字化方案及快速算法的正确性。

multi-channel correlators are widely used in traditional pseudo-random code cw radar,which makes the ranging system more complicated.this paper proposes a method of digitalizing the return signal directly and then convoluting the signals on dsp,which can replace multi-channel correlation in analog circuit.but the computation of convolution is too huge for the dsp to fulfill.to solve this problem,this paper analyzes five fast algorithms including fft,and then chooses one according to the characters of prc-cw radars.the digital method and fast algorithm have been verified by simulated signal and real signal.

摘 要：传统的伪码调相连续波雷达采用多路模拟相关电路实现对回波信号的相关接收，通过多路试探搜索各距离单元的目标，电路复杂。提出的数字化方案，对回波信号直接数字化，利用高速dsp实现数字卷积，可替代多路模拟相关电路。但是直接卷积的运算量过大，dsp无法承受。本文对此进行了研究，分析了包括fft在内的五种快速算法，结合prc-cw雷达的具体情况，确定了一种适于dsp实现的快速卷积算法。仿真和实测数据证实了数字化方案及快速算法的正确性。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。