This dissertation researched a kind of waveform generators . the waveform generator was based on the dds technology and was realized as a pci card . it could generate hybrid modulated signals such as fsk / psk , and it could also generate some other signals 本论文设计并实现了一种波形发生器,波形发生器基于dds原理,模块规范为pci总线插卡形式,产生fsk / psk复合调制信号,同时可产生其它多种信号。
Since the envelope of modulated signal fluctuates , these methods generate unwanted intermodulation distortion ( imd ) products in a nonlinear radio frequency ( rf ) power amplifier ( pa ) . so it is necessary to use linearization technique to reduce the adjacent channel interference ( aci ) 但包络变化的调制信号经过非线性射频功放后会产生交调分量，因此必须采用线性化技术来减少由此产生的邻道干扰。
The circuit models , modulated signal models and error simulation models of the two tdm were established , then by use of computer simulation , the power measurement model errors and instrument errors of the two tdm were fully analyzed by nature and quantification 建立了该两种乘法器的物理模型、数学模型和误差仿真模型，全面地分析了各种参量对其交流功率测量的原理误差和仪器误差的影响，并给出了定量的结果。
In high - speed direct optical modulation of laser diodes , the frequency chirp of the modulated signal cannot be eliminated . then the optical external modulators play more and more important role in large capacity optical transmission systems , and have become a subject of intense study 在高速光调制中，直接调制引起的啁啾噪声难以克服，光外调制器在大容量光纤传输系统中，扮演着越来越重要的角色，成为当前的研究热点。
The vibration signal is decomposed into several intrinsic mode functions ( imfs ) by emd , and the fault information is extracted from the imfs containing modulated signals , which then is effectively separated by emd , thereby the signal to noise ratio ( snr ) of diagnosis signal is improved obviously 首先，对复杂的振动信号进行经验模式分解，得到若干个基本模式分量，再对包含调制信号的基本式分量进行包络分析以提取故障信息。
The auxiliary modulating signals of the current controller at the rectifier and the extinction angle controller at the inverter , and the reference voltage of exciter are chosen to be control variables . then the all - state feedback linear optimal controller is designed 以直流系统整流侧电流控制器的辅助调节信号、逆变侧关断角控制器的辅助调节信号以及励磁系统参考电压作为控制变量,设计了系统的全状态反馈线性最优控制器。
This waveform library not only contains those typical radar signals like single - carrier frequency signal , encoded signal , lfm etc , but also include many hybrid modulated signals , like fsk / psk signal , fsk / ppm signal , psk / ppm signal , pseudo - random fsk / psk signal , etc . we use visual c + + 6 . 0 to implement this software program , this makes it easy in control operation and provides a nice human - machine interactive interface 波形库中既包含了传统的雷达波形，如单载频脉冲信号、 lfm 、编码信号等，又包括了复合调制波形，如fsk / psk信号、 fsk / ppm信号、 psk / ppm信号、伪随机fsk / psk信号等。采用vc编程实现，使其具有友好的人机界面和灵活的控制操作。
A modulated signal of rect ( tt / pw ) added by a zero mean uniform noise . is demonstrated for 2 - d dependence of the waveform on time and trials and 2 - d dependence of spectrum on frequency and trials to show different time domain and frequency domain properties of a random process including noise and signal 以双边递减波电压讯号加上含有准常态杂讯为例，图示含有杂讯电压讯号其波形随时间及试验之二维变动及频谱随频率及试验之二维变动，显示杂讯与讯号之随机过程在时域与频域之不同特性。
According to the following design theory : the dsp calculates in real time and produces three phases spwm waves to control the on or off of the 6 igbts in ipm respectively . ipm then inverts the commutated single phase direct current ( insulated gate bipolar transistor ) into three phases alternating current . when modulated signals of spwm are changed , the on - off time of switches also changes , so as to the voltage and frequency of output signals 本文提出了一种基于dsp (数字信号处理器tms320f240 )的通用的三相间接变频电源系统，利用分段同步调制法和混合查表法，实时计算不同频率下的采样周期、电压幅值、输出脉宽，产生双极性spwm波形，经驱动放大后用于ipm ( intelligentpowermodule )中的绝缘栅双极型晶体管栅级驱动，以控制电源的输出电压和频率，实现变频电源的智能数字控制。
A modulated signal of rect ( tt / pw ) added by a zero mean uniform noise . is demonstrated for 2 - d dependence of the waveform on time and trials and 2 - d dependence of spectrum on frequency and trials to show different time domain and frequency domain properties of a random process including noise and signal 以方波电压讯号加上均匀杂讯乘以无杂讯载波之调变讯号为例，图示含有杂讯电压讯号其波形随时间及试验之二维变动及频谱随频率及试验之二维变动，显示杂讯与讯号之随机过程在时域与频域之不同特性。
