Electronic and Communication - Engineering

Abstract: During the last decade, smart cards have become a widespread digital device. Advantages of smart cards are, for instance, low development costs and thepossibility to obtain a high degree of stability and security. They are frequently used for sensitive applications like money withdrawal or identification systems. The secured identification mechanism of smart cards depends on protocol which can be built in optimized hardware by using a Hash function whereas the heart core for any Hash function is an encryption cipher.

Abstract:While the aircraft flying above the earth surface, the signal transmitted

Abstract:This work focuses on the synchronization in orthogonal frequency division multiplexing (OFDM) systems, which arises to be one of the most critical operations. The OFDM system is explained in details and the synchronization problems occurring in this system are classified with the techniques used to overcome these problems. These techniques are 1-“maximum likelihood estimation” for timing and frequency offset, 2-the “Schmidl and Cox” timing and frequency offset estimation, and 3-synchronization of IEEE 802.11a standard signal or wireless LANs (WLAN).