数字信号处理

Abstraction :This paper analyzes the principle of Butterworth digital filter,discuss bilinear transformation method of filter design;record a piece of voice by Microsoft voice recorders, carry on its a time-domain analysis, spectral analysis;then design a specified Butterworth band-stop filter based on the theory of bilinear transform,analyze the filter by the tool named Fvtool;and filter the voice signal acquired by voice recorder.finally compare its characteristics of frequency domain and time domain,study the applications of Butterworth filter in digital signal processing ,in particular in signal denoising.

本文分析了巴特沃思数字滤波器的原理，探讨了双线性变换法设计滤波器的方法；用微软录音机采集一段语音，对其进行了时域分析，频谱分析；然后使用双线性变换法设计了一个的巴特沃思带阻滤波器，并且使用fvtool对设计的滤波器进行分析；然后利用该滤波器对采集的语音信号进行滤波。最后对比滤波前后的语音信号的时域和频域特性，研究了巴特沃思滤波器在信号处理尤其是信号滤波去噪方面的特性和应用。

The study and application of the primary current limiting harmonic excluder for the type of the thermal resistor ;2. A recorder based on the thermal resistor s is used to monitor and record the state of the dielectric sample which is put into HV square wave life testing.

该仪器通过PTC 热敏电阻监测高压回路中限流电阻温度变化提取介质击穿信号，以单片机AT89c55为运算控制中心，采用热信号时间差分数字算法处理及控制信号。

A method for shifting a pitch of acoustic signals, which are expressed in terms of a series of digital signals, to an optional pitch, uses a compacting and/or expanding process on the time axis and cross-fades a fade-in acoustic signal, stored in a memory.

一种音程变换方法，用时间轴压缩扩展和交叉渐变处理将数字信号序列表示的音响信号的音程变换为任意音程。将音响信号存储到存储器中。

In the second part, we studied blind source separation in ill conditioned cases, obtained the sufficient and necessary conditions on solvability, and presented the neural network model and corresponding adaptive algorithm. We also discussed the blind digital source separation, established the blind separation and extration models and algorithms. These algorithms can be used to deal with high noise and ill-conditioned cases.

在第二部分，我们研究了奇异混合情形下信号盲分离问题，给出了神经网络模型及相应的自适应算法；我们也研究了数字信号盲分离问题，得到了有关可解性的充要条件，提出了分别处理低噪声问题和高噪声问题的算法，这些算法对感知信号个数少于源信号个数等病态问题也适用。

Data acquisition is to invert analogy signal to digital signal, and then send it to the computer.

数据采集部分主要是从模拟信号源中采集信号并将之转换为数字信号送计算机处理。

The main features of the system are: the communications line is not only used for data transmission but also responsible for the system control and management; only one analogue to digital converter is needed for the whole system; a digital trimmer which is analogous to the adjustable resister in function is installed to each sub—system.

本文所进行的数字型条干均匀度测试仪的系统设计，采用了多微处理器的分布式并行结构，提出了一种数字信号的总线结构，采取了数据预处理和数字微调等措施，其主要特点为：半双工异步通信线不但用于数据传输，而且还负责系统的控制和管理；整个系统只需一路模数转换器；各子系统均设有数字微调装置，其功能类似于模拟电路中的电位器，可独立进行参数调整。

This system includes three units of signals' sample,processing, and display.

本文设计了以DSP作为中央处理器的数字电路系统，包括信号的采集、处理、显示三个单元，实现了对整个系统的控制与信号处理。

A design and implementation method of the high speed modulation system, which adopted the new techniques of the FPGA and DAC based communication system,is presented in this paper. The effect of the key techniques of this system, such as the high speed digital signal processing for modulation, high speed based-band signal conversion, wide-band modulation, carrier suppression, high frequency and high precision system clock generation, is analyzed, and the solutions and performance analysis is also given. Finally, a high speed modulation system for space applications is implemented, can be used for high speed data transmission with QPSK, 8PSK, QAM or other kinds of digital modulation.

本论文依据正交调制原理，采用基于FPGA和DAC的设计技术，提出了一种高速、灵活的调制系统的设计方法，重点分析了系统组成的调制编码映射、基带脉冲信号转换、信号滤波、调制、系统时钟产生等关键技术环节的影响，解决了高速调制信号处理、高速数据转换、宽带调制、载波抑制、高频率高精度系统时钟的产生等关键技术问题，完成了一种适用于空间应用的高传输速率、多进制数字调制方式和调制体制灵活的数据传输调制系统的设计与实现，可在硬件设计不变的情况下，实现QPSK、8PSK和16QAM等多种调制方式的高速数据传输，QPSK调制速率达到500Mbps。

Compared with the prior art, the invention has the advantages that:(1) the active neural microelectrode integrates signal collection/processing and stimulation function in the same preposed signal processing chip, which can reduce the disturbance of environmental noise, inhibit the attenuation caused by parasitic capacitance, filter polarized voltage and greatly improve the speech-noise ratio and stability of the whole microelectrode; and (2) the active neural microelectrode integrates digital logic control and stimulation circuit in the chip, so as to reduce the amount of output leads and simplify the complexity of subsequent circuits.

本发明相对于现有技术具有如下突出特点：(1)将信号的采集，处理以及刺激功能集成在一个前置信号处理芯片上，不仅减少了因为环境噪声的干扰，而且很好的抑制了寄生电容引起的衰减，滤除了极化电压，大大增强了整个微电极的信噪比和稳定性；(2)同时，将数字逻辑控制和刺激电路也集成在此芯片上，减少了输出引线的数目，简化了后续电路的复杂性。

This graduated design program, data collection ware produce is the only flat machine of 89 C51 that uses the company of ATMEL with AD0809 chip do a collection simulated voltage signal, conversion number word signal passes string mouth again by only flat machine to dispatch to the handling of personal computer, additionally, 3 number pipe LEDs show the digital information of collection.

本次毕业设计课题，数据采集器制作，是利用ATMEL公司的89C51单片机和AD0809芯片做一个采集模拟电压信号，转换为数字信号，再由单片机经过串口发送给PC机处理，另外三个数码管LED显示采集的数字信息。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。