数字信号

X-Digital system company-- the Blackfin processor that ADI firm used in the compositive satellite receiver that a broadcast transmits systematic manufacturer to contain FM modulator in its. X-Digital system company uses Blackfin processor, offerred a kind of such products, promise satellitic operation business to convey digital frequency to still do not have the market that open far-- much resident is unit , for example hotel and apartment building. The satellitic receiver of X-Digital company changes digital satellite signal into the FM imitate signal that can be identified by receiver of consumptive assonance frequency.

X-Digital 系统公司--一家广播传输系统制造商在其带有FM调制器的集成卫星领受器中采用了ADI公司的Blackfin措置器。X-Digital系统公司采用Blackfin措置器，供给了如许一种产物，答应卫星运营商将数字音频传送到远远还没有翻开的市场--多住户单元，例如酒店和公寓大楼。X-Digital公司的卫星领受器将数字卫星信号转换成可被尺度的生产类音频领受器识此外FM模拟信号。

Firstly, oscilloscope control system based on GPIB technique is presented with friendly operation environment to the HIFU system, and it uses multithreading technique in programming to realize real-time recording and display of the signal; Secondly, temperature collection and data recording system is designed, which also could get real-time recording and display of the 16 channel temperature signal, and it's believed to be of great use for further experiments of the HIFU system; Thirdly, multiple ultrasonic phased array's phase shifter is designed,which could provide 8-bit phase control in a range of frequency where the centrical frequency is 1MHZ. Fourthly, the module of serial communication is realized to insure the communication between devices and computer, including both synchronous and asynchronous communication, which enables the system to transfer data reliably and stably; Finally, the module of digital quantity control is accomplished, which provide for upper application the consistent solution to the control of exterior devices via digital interface. It can get or set the devices state using interrupt mode to receive input signal or send output signal.

主要有以下几个方面：设计了基于GPIB的示波器控制系统，给课题的研究工作提供了一个良好的环境，它采用了多线程编程的方法，能够较好的实时显示当前波形并记录数据；设计了温度采集和数据记录系统，能够对16路温度信号进行并行同步的实时采集，用于HIFU剂量学研究中温度场检测和医疗评价；设计了相控阵相位延时电路并且通过调试，满足了课题的相位控制的要求，在中心频率为1MHZ左右的频率范围内都能够达到8-bit相位控制；实现了串口通讯模块，为各项设备与计算机之间的通讯提供保证，它提供同步和异步的通讯能力，使系统能够可靠稳定的传输数据；建立了数字量控制模块，为上层应用程序提供一致的方法使用数字接口控制外部仪器，它使用中断的方式来接收输入或输出设定的开关量信号，从而得到或设定各种仪器的状态。

The apparatus is capable of recording a digital information signal and at least one digital auxiliary signal in a track.

该设备能够把数字信息信号和至少一个数字辅助信号记录在磁道中。

The main task of this paper is a digital watermark image signal, the process is the first image signal by adding a watermark information, the next to detect digital watermark information extraction, the final image of the embedded watermark different attacks, the test of robust watermark sexual.

本次论文任务主要是对图像信号实现数字水印，过程首先是对图像信号加入水印信息，接下来对数字水印信息进行检测抽取，最后对嵌入水印的图象进行不同的攻击，测试水印的鲁棒性。

Multistandard digital video signal conversion is an important technology in display system of Plasma Display Panel structure with Shadow Mask.

多制式数字视频信号转换是荫罩式等离子平板显示系统中的一项重要技术，本文提出了不同制式数字视频信号扫描格式到用于SM-PDP显示的固定分辨率、帧频扫描格式转换的解决方案。

That is to say, by using the special digital converter or running relevant arithmetic, it converts the radio signal to intermediate frequency signal and completes the base-band signal process that isn"t the veriest SR and is named "software defined radio. This paper introduces the rapid system prototype into the design of software radio system, which has great advantage because rapid system prototype technology can be used to describe the future application.

由于受到硬件性能如A／D、D／A及DSP芯片处理速度的限制，目前的软件无线电系统多采用折中的实现方案，增加专用的数字变频器或者运行数字变频算法，将射频信号变频到中频，然后再进行基带信号处理，这样的软件无线电系统又被称之为"软件定义无线电"，它并不是真正意义上的软件无线电。

This paper mainly introduces the baseband transmission and the waveband transmission of digital communication system.

介绍了数字通信系统中信号的基带传输和频带传输；分别论述了基带传输系统和频带传输系统模型，说明了基带信号无码间干扰传输条件及频带数字调制的工作原理。

This paper systematically researched this sort of nonuniformly sampled signals'digital spectrum structure, signal-to-noise ratio , the response of D/A converter with nonuniformly sampled signals, the algorithm for estimating timing offsets, the relationship between the discrete time expression of the total energy and the continuous time expression, the estimation of the average power, the algorithm of recovery and application in designing and analyzing the digital waveform synthesizer.

本文全面系统地研究了这类周期性非均匀采样信号的数字谱结构，信噪比表达式，数模转换器对非均匀采样信号输入的响应，误差校正算法，时域与频域的能量对应关系，对功率测量的影响，内插恢复算法，以及在设计和分析数字波形合成器中的应用。

The speech signal is a analog one, and we can perform its digital transmission by sampling, quantizing and coding.

话音信号是一个模拟信号，通过采样，量化和编码，话音信号是一个模拟信号，通过采样，量化和编码，我们可以实现话音信号的数字传输。

The 5mV of the audio signal which comes from the microphone to linear amplificated by the audio signals amplifier,then mixes with music signals from other sound sources(eg:the tape 、CD) by the hybird amplifier . By the control of the digital volume controller the mixed signal ,then amplificated again by the preamplifier,when integrated power amplifier for idling time realizes the signal enlargement factor respectively is 10、100、1000 times;moreover is capable of delivering 3V of output to a 600%26Omega; load. the amplificate signal makes the loudhailer work at last.

该音频信号放大器能够将来自话筒5mV的音频信号进行线性放大，然后和来自其他音源的音乐信号通过混合放大器来混合，混合后的信号经数字音量控制器对高低频的增益进行提升与衰减，再通过前置放大器放大，当集成功率放大器为空载的时候实现信号的放大倍数分别为10、100、1000倍；另外再实现当负载为600%26Omega；的时候，输出幅度为3V，最后经扬声器发出悦耳的声音。

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。