PhaseLocked Systems Publications (Abstracts)

 Clipping and Quantization in Data Converters (pdf) In this white paper we will show that the degradation induced by A/D quantization and clipping noise in a DSP system is heavily dependent on the signal level and signal type presented to the A/D converter. Standard formulas for computing the degradation do not include the signal level, nor do they account for clipping distortion. The Effects of Timing Jitter on A/D Conversion (pdf) One of the least understood aspects of A/D conversion is the impact that jitter on the sampling clock has on the accuracy of the conversion process. In this whitepaper we will show that the timing jitter has a serious impact on quality of the the conversion process, as well as discuss the effects of the spectrum of the jitter on A/D conversion. Probability Distributions (pdf) This is a quick-reference guide to a few commonly used probability distributions. The key properties of several distributions are tabulated and the text contains brief derivations. Computation of Rice and Noncentral Chi-Squared Probabilities (pdf) This report is a discussion of methods for computing the generalized Marcum Q function. Included is a summary of noncentral chi-squared and Rice random variables, some properties of Marcum's Q function, a discussion of inverting the Q function and details of the methods themselves. A Bessel function series approach, Parl's method, and Dillard's method are all included along with performance comparisons. marcum_1.0.0.tar.gz: Octave package for computing Marcum Q Functions marcum_1.0.0.zip: Octave functions for computing Marcum Q Functions A collection of octave routines for computing the generalized Marcum Q function. The tar.gz file is in octave package format for use with octave's pkg install command. The zip file just contains the routines with MSDOS-style line terminations. WiMedia UWB by Ghobad Heidari, Ph.D. with a chapter by Robert T. Short, Ph.D., John Wiley 2008. UWB (ultra-wideband) has been investigated for many decades but only recently has it become commercially viable. With the advent of WiMedia UWB technology and its associated standard specifications, the stage is set for the next generation of WPAN applications to take root. WiMedia UWB focuses on the ECMA-368 standard. Both PHY layer and MAC sublayers specified in this standard are explained in great detail. The book offers not only the facts about the requirements of the standard, but also the motivation and logic behind them. To give a comprehensive perspective of the UWB technology to the reader, other interrelated topics are also examined in this book. These include the history of UWB and its recent standardization attempts; UWB applications and advantages; UWB spectrum allocation and regulations around the world; UWB platform clients: Certified Wireless USB (CW-USB), Bluetooth, and WLP (WiMedia Link layer Protocol, which enables Internet Protocol over UWB); as well as some important implementation issues and considerations. As the first application of WiMedia UWB, CW-USB is given a special and more comprehensive treatment. Fundamentals of OFDM by Robert T. Short, Ph.D., to be published 2013. A thorough and complete introduction to the theory and practice of OFDM and OFDMA systems.