ABSTRACT
The main objective of this book is to study image encryption from a communication perspective. So, we need to determine if an encryption algorithm fits the communication requirements. It is time now to switch to wireless communication to understand the communication process and its limitations and hence to study the performance of the decryption algorithms after the communication process. We consider multicarrier modulation (MCM), especially orthogonal frequency division multiplexing (OFDM), in our study because it is the new trend in wireless communication systems. MCM is used not only in the physical layer of several wireless network standards such as Institute of Electrical and Electronics Engineers (IEEE) 802.11a, IEEE 802.16a, and HIPERLAN2 (High-Performance Radio Local Area Network Type 2), but also in HDTV (high-definition television) applications that include image communication [111,112]. OFDM overcomes the effects of multipath fading by breaking the signal into several narrow-bandwidth carriers. This results in a low symbol rate reducing the amount of ISI (intersymbol interference). The high tolerance to multipath fading makes OFDM more suited to transmissions with a high data rate in terrestrial environments compared to singlecarrier transmissions.
