查询词典 frequency modulation

The invention comprises the following steps: summating and counting the added playing times of the acoustic frequency song in the portable media device when playing any acoustic frequency song; updating and saving in the current playing acoustic frequency song list; displaying the first acoustic frequency song list and the second acoustic frequency song list for the users in the picture according to the summated and counted acoustic frequency song playing frequency and the updated and saved current playing acoustic frequency song list when the user requests to play the song and uses the quick search music function; displaying the acoustic frequency song list according to the high sequence of the user playing frequency.

本发明包括：在便携式多媒体设备中，当播放任意音频曲目时，对该音频曲目增加的播放次数进行累积计数，并在最近播放的音频曲目列表中进行更新存储，当使用者要求播放曲目而使用快速检索音乐功能时，便能参照累积计数的音频曲目播放频度和被更新存储的最近播放的音频曲目列表，在画面中显示可供使用者选择的第1音频曲目列表和第2音频曲目列表，按照使用者播放频度高的顺序以及最近播放的顺序显示音频曲目列表。

The invention discloses a multi-cell pilot frequency distribution method applied in an orthogonal frequency-division multiplexing system, which comprises the following steps: generating at least two different original frequency hopping sequences according to a predetermined pilot frequency domain; generating a combined frequency hopping sequence (having length greater than that of the original frequency hopping sequences) from at least two different original frequency hopping sequences; generating different pilot frequency structures satisfying collision threshold requirements based on the combined frequency hopping sequence; and distributing the generated pilot frequency structures to each cell.

本发明公开了一种多小区导频分配的方法，用于正交频分复用系统，按照预定的导频频域间隔生成至少两种不同的原始跳频序列；将至少两种不同的所述原始跳频序列生成组合跳频序列，所述组合跳频序列的长度大于所述原始跳频序列的长度；基于所述组合跳频序列生成满足碰撞门限要求的不同导频结构；将所述生成的导频结构分配给各小区。

The article presents the developing condition of PWM and SVPWM first.Then the theory of SVPWM is discussed in detail.The SVPWM is based on the thought of magnetic chain tracking.It makes the ideal magnetic chain circle of three-phased sysmmetry electric motor supplied by three-phased sysmmetry sine wave voltage for basis,uses the practical magnetic chain vector formed by the different switch modes of three-phased inverter to track the basic magnetic chain circle.During the course of tracking,the inverter changes the switch modes properly to form the PWM waves.Then the modulation wave of SVPWM is analyzed in detail.The modulation wave of SVPWM is implicit,but the analogous modulation wave in A-B-C axis needs to be calculated in order to expose the internal relation of SVPWM and SPWM.That is to show the implicit modulation wave of SVPWM. SVPWM actually is a transformed SPWM ruly sampled by the modulation wave which is injected by the zero prefaces based on space vectors.

本文首先对脉宽调制技术的发展现状进行了综述，在此基础上分析了电压空间矢量脉宽调制技术的发展现状；接着对空间电压矢量脉宽调制技术的基本原理进行了详细的分析和推导，SVPWM是基于磁链追踪的思想，它以三相对称正弦波电压供电下三相对称电动机定子理想磁链圆为基准，由三相逆变器不同开关模式下所形成的实际磁链矢量来追踪基准磁链圆的，在追踪的过程中，逆变器的开关模式作适当的切换，从而形成PWM波；然后详细分析了电压空间矢量脉宽调制技术的调制波，虽然SVPWM法的调制波是隐含的，但是为了揭示SVPWM法与SPWM法的内在联系，需要求出SVPWM在A-B-C坐标系上的等效调制波，也就是将SVPWM的隐含调制波显化；SVPWM实质是一种基于空间矢量在三相正弦波中注入了零序分量的调制波进行规则采样的一种变形SPWM。

The results showed that the echolocation calls of the leaf-nosed bats were constant frequency-frequency modulation signals with 2-3 harmonics and the second one among these three harmonics was its dominant frequency. The constant frequency components of three harmonics (Mean±SD, n=18 ) were 33.3±0.2 kHz, 66.5±0.3 kHz, and 99.4±0.5 kHz, respectively. In examined FTCs of 72 IC neurons, their Q 10 -dB values ranged from 0.5 to 95.4 (9.2±14.6) and the neurons whose best frequency around the dominant frequency had sharp frequency tuning.

结果发现，大蹄蝠回声定位叫声为恒频-调频(constant frequency-frequency modulated，CF-FM)信号，一般含有2~3个谐波，第二谐波为其主频，CF成分频率(Mean±SD，n=18)依次为：(33.3±0.2)、(66.5±0.3)、(99.4±0.5)kHz；电生理实验共获得72个神经元的频率调谐曲线，Q10-dB值的范围是0.5~95.4(9.2±14.6， n=72)，最佳频率(best frequency，BF)在回声定位主频附近的神经元具有尖锐的频率调谐特性。

Common AM, with bilateral, residual sideband and single sideband modulation, and so is the amplitude modulation of a few typical examples, and frequency modulation modulation in the point of view is widely used.

常见的调幅、双边带、残留边带和单边带等调制就是幅度调制的几个典型实例；而频率调制就是角度调制中被广泛采用的一种。

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。

This design paper introduced one kind based on the DSP chip entire numerical control single-phase frequency changer design, along with the frequency conversion velocity modulation technology unceasing development, the frequency changer application is more and more widespread, the frequency changer besides has the remarkable velocity modulation performance, but also has the remarkable energy conservation function, is the enterprise technological transformations and the

本设计论文介绍了一种基于DSP芯片的全数字控制单相变频器的设计，随着变频调速技术的不断发展，变频器的应用越来越广泛，变频器除了具有卓越的调速性能之外，还有显著的节能作用，是企业技术改造和产品更新换代的理想调速装置。

This design paper introduced one kind based on the DSP chip entire numerical control single-phase frequency changer design, along with the frequency conversion velocity modulation technology unceasing development, the frequency changer application is more and more widespread, the frequency changer besides has the remarkable velocity modulation performance, but also has the remarkable energy conservation function, is the enterprise technological transformations and the product renewal ideal speeder.

本设计论文介绍了一种基于DSP芯片的全数字控制单相变频器的设计，随着变频调速技术的不断发展，变频器的应用越来越广泛，变频器除了具有卓越的调速性能之外，还有显著的节能作用，是企业技术改造和产品更新换代的理想调速装置。

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。

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。

"Yes, now you can give yourself airs," she said, you have got what you wanted.

"对了，您现在高兴了，"她说道，这是您所期待的。

Then the LORD said to me: Rebel Israel is inwardly more just than traitorous Judah.

上主于是对我说：＂失节的以色列比失信的犹大，更显得正义。