Studying And Analyzing the modulators and demodulators of PCM

Modulating signals of transmission stations to reception stations is a key factor to guarantee the best possible transmission and reception of these signals .Digital modulation represents a huge evolution in communication field and modulation, which used to depend on analog signal modulation of one parameter-Amplitude . frequency or phase. Digital modulation depends on transforming the transmitted data signal (Bits) and then sending it as samples, and changed back into an analog signals in reception station . In digital systems, digital data are transformed into analog data in the transmitter and does the reverse in the receiver. In digital transmission, on the other hand, as in wired local area networks (WLAN), Digital data are transmitted in their digital state.

A Methodology for linking local coordinates system in Juba Darius with Public Coordinates System in Syria

Search includes the geodetic study local network triangulation real estate in Slenfeh area, and propose a solution for the local network linking public real estate network in Syria based on a comparison of the 2D-Transformation results so as to choose the optimal conversion which avoids the occurrence of interactions between regions and schemes real estate and reduces distortions network after conversion (shift, rotation, scale). At first been touched to date geodesic network set up in Slenfeh region and the stages of execution, and the problems of engineering, and then to the transformation methods used in the link, and apply them to the network, and choose the best conversion, and set parameters optimal transformation, have been proposed solution depends on the network is divided into three segments so that Network least deformation resulting from the transformation in each sector. A computer program that has been prepared for the implementation of the transformation and linking local grid points by using the C # programming language. It has been verified the resultant transformation parameters by comparing linear measurements calculated from coordinates resulting from the transformation with linear measurements in the network observation records, and execution field measurements of some of the points and calculate its coordinates and compare it with the coordinates calculating fromtransformation.