چكيده به لاتين
Given the growing demand for data in mobile phones, the fifth generation of telecommunications networks intends to use the existing spectrum of mm wave in order to increase the communication capacity. due to this, the mm wave of high technology is used to overcome this lack of bandwidth and thus increasing the data rate.On the other hand, in order to overcome the weakness of the mm wave propagation, MIMO systems were widely considered with the design of analog / digital combination encoder and receiver architecture in millimeter - wave systems. however, physical layer security in mm wave systems and especially the safe design problem of beamforming in these systems is not well considered. in this thesis, a multi user system has been investigated in the presence of an eavesdropper. In addition to increasing the number of users in addition to improving the information rate, the confidentiality is also increased. in this thesis, we try to establish a compromise between reliable transmission of information and increasing the confidentiality of each user; so the problem is that the sum of the confidentiality of all users is maximum with the presence of an eavesdropper. Since the design problem is non - convex, there will be no appropriate and efficient response; hence, we use the method based on the SVD logic to design the combinatorial optimization problem and solve this problem in a way that is based on the use of the user bases to achieve an optimal solution. finally, with the help of mathematical solutions and computer simulation, we show that in addition to improving wireless transmission, there is an appropriate confidentiality rate compared to the recent methods.
