Contents I. Introduction
The democratization of mobile telephony from the 1980s gave the freedom to make and receive phone calls to a wide public and, later, all kind of data transfers such as short messages, documents or videos. With the increasing demand for data rate and transfer speed, mobile communication systems overcame different stages of evolution according to this permanent increase of data amount. Today, this data rate speed reaches up to 100 Mbits/s for 4th generation systems and can be improved up to 1 Gbits/s [1]. The objective for 5th next generation (5G) systems is to achieve a speed of 20 Gbits/s that will constitute one of pieces in the jigsaw to realize the concept of smart city [1]–[2].
