Personal Communications Services (PCS) require low-power radio technologies. One such transceiver architecture employing frequency-hopped spread-spectrum techniques is presented. System features such as antenna diversity with equal-gain combining and sequential hop combining are incorporated into the transceiver design to achieve robust wireless digital data transmission over fading channels. A...

High-resolution low-power Direct Digital Frequency Synthesizers (DDFS) with small chip area are investigated. Lookup tables for sine and cosine yield the leading bits of the amplitudes. A CORDIC interpolation scheme enhances the amplitude precision. Systematic case studies using VHDL – models and synthesis indicate, that optimum LUT/CORDIC ratios can minimize use of power and silicon area. Intr...

The synthesis of digital circuits for the solution of binary classification problems is performed by employing a new learning method, named Hamming Clustering: it proceeds by generating clusters of input patterns that belong to the same class and are close each other according to the Hamming distance. In polynomial time, a digital circuit is obtained, neglecting redundant inputs irrelevant to t...

-Idea of Radar target simulator is to electronically generate the Radar illuminated environment without switching on actual Radar transmitter in the field. These Radar target simulators are used to develop, optimize and test the Radar System Design and Algorithms in the Lab. Conventional testing method has its own limitations. In this paper DRFM based target simulator is presented which overcom...

A scheme of frequency hopping spread spectrum (FHSS) frequency synthesizer suitable for synthesis of radio-frequency (RF) carrier signal in very high frequency (VHF) band is proposed, implemented and tested. The synthesizer is based on the direct digital frequency synthesis (DDFS or DDS) and phase locked loop (PLL) with dynamic monitoring of varicap’s voltage to reduce switching time. The resul...

successful endodontic therapy depends on adequate mechanical and chemical debridement of the canal which requires knowledge of the canal morphology. conventional radiography has been used to evaluate the canal type; however, direct digital radiography has recently been practiced for this purpose due to the shortcomings of conventional radiography. the aim of the present study was to compare the...

Background and Purpose:  Due to the important role of imaging in the diagnosis and treatment plan in orthodontics, CBCT (Cone Beam Computed Tomography) images because of their three-dimensional nature, can minimize the disadvantages of two-dimensional images such as magnification, distortion, or superimposition. The purpose of this study was to evaluate the accuracy of conventional cephalograms...

Computer systems designed for music synthesis usually encapsulate signal-processing algorithms as macros or functions, and thus provide a modular interface which facilitates the development of complex structures. This is the thinking behind Mathews’ original concept of the ‘‘unit generator’’ (Mathews 1969) and most subsequent software synthesis languages use this approach. While it has proven t...