In this thesis, the problem of Physical Layer (PHY) Security is considered. This problem
deals with secure signal transmission for a Multiple-Input Multiple-Output (MIMO) system
using a relay ie the signal is transmitted in such a way so that even if it is received by some
illegal receiver, called as the eavesdropper, besides the intended receiver, the former will
not be able to decode it. This problem occurs in all wireless communication systems which
use broadcast technique since in this technique, the signal is received by every receiver …