ACPR (adjacent channel power ratio), AltCPR (alternatechannel power ratio), and noise are iMportant performancemetrics for digital communication systems thatuse, for example, WCDMA (wideband code division multipleaccess) modulation. ACPR and AltCPR are bothmeasures of spectral regrowth. The power in the WCDMAcarrier is measured using a 5MHz measurement bandwidth;see Figure 1. In the case of ACPR, the total powerin a 3.84MHz bandwidth centered at 5MHz (the carrierspacing) away from the center of the outermost carrier ismeasured and compared to the carrier power. The resultis expressed in dBc. For AltCPR, the procedure is thesame, except we center the measurement 10MHz awayfrom the center of the outermost carrier.
上传时间: 2013-11-02
上传用户:maricle
Accurate measurement of the third order intercept pointfor low distortion IC products such as the LT5514 requirescertain precautions to be observed in the test setup andtesting procedure. The LT5514 linearity performance ishigh enough to push the test equipment and test set-up totheir limits. A method for accurate measurement of thirdorder intermodulation products, IM3, with standard testequipment is outlined below.It is also iMportant to correctly interpret the LT5514specification with respect to ROUT, and the impact ofdemo-board transmission-line termination loss whenevaluating the linearity performance, as explained in theLT5514 Datasheet and in Note 1 of this document.
上传时间: 2013-11-14
上传用户:l254587896
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
随着USB技术日趋成熟,USB开发者只需要关注顶层开发即可,这样虽然减少了工作量,但容易使开发者忽略USB基础理论与概念,导致的弊端在于开发者一旦遇到问题,往往不知如何解决。作者基于多年USB开发经验,针对当前很多USB开发者容易混淆的概念,进行深入浅出的剖析,针对枚举和重枚举的区别、不同启动方式的区别等问题,进行了归纳总结。本文从对比的角度分析问题,有助于开发者理清USB的工作机理。
标签: USB
上传时间: 2013-10-26
上传用户:zaocan888
CGAL is a collaborative effort of several sites in Europe and Israel. The goal is to make the most iMportant of the solutions and methods developed in computational geometry available to users in industry and academia in a C++ library. The goal is to provide easy access to useful, reliable geometric algorithms
标签: collaborative several Europe Israel
上传时间: 2015-01-09
上传用户:refent
CGAL is a collaborative effort of several sites in Europe and Israel. The goal is to make the most iMportant of the solutions and methods developed in computational geometry available to users in industry and academia in a C++ library.
标签: collaborative several Europe Israel
上传时间: 2015-04-10
上传用户:hopy
The module LSQ is for unconstrained linear least-squares fitting. It is based upon Applied Statistics algorithm AS 274 (see comments at the start of the module). A planar-rotation algorithm is used to update the QR- factorization. This makes it suitable for updating regressions as more data become available. The module contains a test for singularities which is simpler and quicker than calculating the singular-value decomposition. An iMportant feature of the algorithm is that it does not square the condition number. The matrix X X is not formed. Hence it is suitable for ill- conditioned problems, such as fitting polynomials. By taking advantage of the MODULE facility, it has been possible to remove many of the arguments to routines. Apart from the new function VARPRD, and a back-substitution routine BKSUB2 which it calls, the routines behave as in AS 274.
标签: least-squares unconstrained Statisti Applied
上传时间: 2015-05-14
上传用户:aig85
This PNG Delphi version 1.56 documentation (this version is a major rewrite intended to replace the previous version, 1.2). Improvements in this new version includes: This new version allows the programmer to not use Delphi heavy units which will greatly reduce the size of the final executable. Read more about this feature here. Most, if not all, Portable Network Graphics features as CRC checking are now fully performed. Error on broken images are now better handled using new exception classes. The images may be saved using interlaced mode also. Transparency information won t be discarted after the image is loaded any more. Most of the images are decoded much faster now. The images will be better encoded using fresh new algorithms. iMportant! Now transparency information is used to display images.
标签: version documentation intended rewrite
上传时间: 2015-06-28
上传用户:qiao8960
Person-to-person realtime IP communications, like presence, VoIP and video applications, offer clear benefits for the enterprise as time- and money-savers. Unified functionality is now available, where all of the above are integrated into one streamlined application and interconnect with other networks. This creates a very iMportant business tool and usage is increasing.
标签: Person-to-person communications applications realtime
上传时间: 2015-06-28
上传用户:维子哥哥
This book is about the management of business processes. This is certainly not a new topic. Since the beginning of the Industrial Revolution, it has been written about from every possible point of view—economic, sociological, psychological, accountancy, mechanical engineering and business administration. In this book, we examine the management of business processes from the perspective of computing, or—to put it more broadly—of information technology. The reason is that information technology has made huge leaps forward in recent years, resulting in the creation of completely new ways of organizing business processes. The development of generic software packages for managing business processes—so-called workflow management systems (WFMS)—is particularly iMportant in this respect.
标签: This management certainly processes
上传时间: 2013-11-29
上传用户:shus521