this is the second part of Introducing wimax and its physical layer
标签： Introducing physical second layer
上传时间： 2014-11-26
上传用户：zhengjian
this pdf Introducing the gsm technology , types of modulation ang its network parts
标签： Introducing modulation technology network
上传时间： 2013-12-27
上传用户：fredguo
ebook Introducing notion of "object" in C++
标签： Introducing notion object ebook
上传时间： 2017-08-24
上传用户：ikemada
数字控制的交流调速系统所选用的微处理器、功率器件及产生PWM波的方法是影响交流调速系统性能好坏的直接因素。在介绍了正弦脉宽调制(SPWM)技术的基础上，设计了一种以8098单片机作为控制器，以智能功率模块IPM为开关器件的变频调速系统。通过软件编程，产生正弦脉冲宽度调制波形来控制绝缘栅双极晶体管的导通和关断，从而达到控制异步电动机转速的目的。实验结果表明，该系统可调频率调电压，稳定度高，调速范围宽，具有较强的实用价值 Abstract: AC variable speed with digital control systems used microprocessors， power devices and generate PWM wave is the direct factors of affecting the performance AC speed regulation system. On the basis of Introducing the sinusoidal pulse width modulation (SPWM) technology，this paper designed variable speed system which used 8098 as a controller， intelligent power module IPM as switching device. Through software programming， resulting in sinusoidal pulse width modulation waveform to control the insulated gate bipolar transistor turn on and off， so as to achieve the purpose of speed control of induction motors. Experimental results show that the system can adjust frequency modulation voltage， high stability， wide speed range， has a strong practical value.
上传时间： 2013-11-14
上传用户：ynwbosss
波长信号的解调是实现光纤光栅传感网络的关键，基于现有的光纤光栅传感器解调方法，提出一种基于FPGA的双匹配光纤光栅解调方法，此系统是一种高速率、高精度、低成本的解调系统，并且通过引入双匹配光栅有效地克服了双值问题同时扩大了检测范围。分析了光纤光栅的测温原理并给出了该方案软硬件设计，综合考虑系统的解调精度和FPGA的处理速度给出了基于拉格朗日的曲线拟合算法。 Abstract: Sensor is one of the most important application of the fiber grating. Wavelength signal demodulating is the key techniques to carry out fiber grating sensing network， based on several existing methods of fiber grating sensor demodulation inadequate， a two-match fiber grating demodulation method was presented. This system is a high-speed， high precision， low-cost demodulation system. And by Introducing a two-match grating effectively overcomes the problem of double value while expands the scope of testing. This paper analyzes the principle of fiber Bragg grating temperature and gives the software and hardware design of the program. Considering the system of demodulation accuracy and processing speed of FPGA，this paper gives the curve fitting algorithm based on Lagrange.
上传时间： 2014-07-24
上传用户：caiguoqing
波长信号的解调是实现光纤光栅传感网络的关键，基于现有的光纤光栅传感器解调方法，提出一种基于FPGA的双匹配光纤光栅解调方法，此系统是一种高速率、高精度、低成本的解调系统，并且通过引入双匹配光栅有效地克服了双值问题同时扩大了检测范围。分析了光纤光栅的测温原理并给出了该方案软硬件设计，综合考虑系统的解调精度和FPGA的处理速度给出了基于拉格朗日的曲线拟合算法。 Abstract: Sensor is one of the most important application of the fiber grating. Wavelength signal demodulating is the key techniques to carry out fiber grating sensing network， based on several existing methods of fiber grating sensor demodulation inadequate， a two-match fiber grating demodulation method was presented. This system is a high-speed， high precision， low-cost demodulation system. And by Introducing a two-match grating effectively overcomes the problem of double value while expands the scope of testing. This paper analyzes the principle of fiber Bragg grating temperature and gives the software and hardware design of the program. Considering the system of demodulation accuracy and processing speed of FPGA，this paper gives the curve fitting algorithm based on Lagrange.
上传时间： 2013-10-10
上传用户：zxc23456789
Frequently, voltage reference stability and noise defi nemeasurement limits in instrumentation systems. In particular,reference noise often sets stable resolution limits.Reference voltages have decreased with the continuingdrop in system power supply voltages, making referencenoise increasingly important. The compressed signalprocessing range mandates a commensurate reductionin reference noise to maintain resolution. Noise ultimatelytranslates into quantization uncertainty in A to D converters,Introducing jitter in applications such as scales, inertialnavigation systems, infrared thermography, DVMs andmedical imaging apparatus. A new low voltage reference,the LTC6655, has only 0.3ppm (775nV) noise at 2.5VOUT.Figure 1 lists salient specifi cations in tabular form. Accuracyand temperature coeffi cient are characteristic ofhigh grade, low voltage references. 0.1Hz to 10Hz noise,particularly noteworthy, is unequalled by any low voltageelectronic reference.
上传时间： 2013-10-30
上传用户：wxhwjf
介绍几种cpuThe 8xC251SA/SB/SP/SQ improves on the MCS-51 architecture and peripheral features, Introducing the advanced register based CPU architecture i.e., the MCS 251 microcontroller architecture. The register based CPU supports a 40-byte register file. In addition, the 8xC251SA/SB/SP/SQ microcontroller has 256-Kbyte expanded external code/data memory space and 64-Kbyte stack space. The new controller is also specially designed to execute C code efficiently. More importantly, the 8xC251SA/SB/SP/SQ maintains binary code compatibility with MCS 51 microcontrollers but at the same time allows the use of the powerful MCS 251 microcontroller instruction set, with many new 8, 16 and 32 bit instructions available. The 8xC251SA/SB/SP/SQ has 512 bytes or 1 Kbyte of on-chip data RAM options and is available in 16 Kbytes and 8 Kbytes of on-chip ROM/OTPROM or ROMless options.
标签： architecture introducin peripheral improves
上传时间： 2015-03-15
上传用户：ccclll
Text processing often involves matching text against a pattern. Although Java s character and assorted string classes offerlow- levelpattern- matching support, that support commonly leads to complex code. To help you write simplerpattern- matching code, Java provides regular expressions. After Introducing you to terminology and thejava.util. regex package, Jeff Friesen explores many regular expression constructs supported by that package s Pattern class. Then he examines Pattern s methods and the additionaljava.util. regex classes. In conclusion, he presents a practical application of regular expressions.
标签： processing character Although involves
上传时间： 2014-01-19
上传用户：爱死爱死
Mobile phones are constantly decreasing in size, thereby complicating the acoustical functionality. Signal processing methods can be used to partially mitigate this problem. In this paper we suggest a method which uses multiple spectral subtraction functions and two microphones, Introducing only a short signal delay.
标签： functionality complicating acoustical constantly
上传时间： 2015-11-15
上传用户：youth25
