Progress of Digital Communication Technology

—Fading Phenomenon and Changes in Compensation Technology—

Abstract

In wireless communications, since transmitted signals are scattered from many objects, many propagation paths with different time delays are formed. When transmitting and receiving while moving in such an environment, received signals will be affected by intricate selective fading in both the frequency and time domains. In this technical note, first, the mechanism of fading phenomena is clarified, changes in previous phase compensation technology are surveyed, and a foundation for digital wireless-communications technology is provided.