  In this paper, we propose a device to device (D2D) communication scenario
underlaying a cellular network where both D2D and cellular users (CUs) are
discrete power-rate systems with limited feedback from the receivers. It is
assumed that there exists an adversary which wants to eavesdrop on the
information transmission from the base station (BS) to CUs. Since D2D
communication shares the same spectrum with cellular network, cross
interference must be considered. However, when secrecy capacity is considered,
the interference caused by D2D communication can help to improve the secrecy
communications by confusing the eavesdroppers. Since both systems share the
same spectrum, cross interference must be considered. We formulate the proposed
resource allocation into an optimization problem whose objective is to maximize
the average transmission rate of D2D pair in the presence of the cellular
communications under average transmission power constraint. For the cellular
network, we require a minimum average achievable secrecy rate in the absence of
D2D communication as well as a maximum secrecy outage probability in the
presence of D2D communication which should be satisfied. Due to high complexity
convex optimization methods, to solve the proposed optimization problem, we
apply Particle Swarm Optimization (PSO) which is an evolutionary approach.
Moreover, we model and study the error in the feedback channel and the
imperfectness of channel distribution information (CDI) using parametric and
nonparametric methods. Finally, the impact of different system parameters on
the performance of the proposed scheme is investigated through simulations. The
performance of the proposed scheme is evaluated using numerical results for
different scenarios.
