3 research outputs found
Resource allocation for D2D links in the FFR and SFR aided cellular downlink
Device-to-device (D2D) communication underlying cellular networks, allows direct transmission between two devices in each other's proximity that reuse the cellular resource blocks in an effort to increase the network capacity and spectrum efficiency. However, this imposes severe interference that degrades the system's performance. This problem may be circumvented by incorporating fractional frequency reuse (FFR) or soft frequency reuse (SFR) in OFDMA cellular networks. By carefully considering the downlink resource reuse of the D2D links, we propose beneficial frequency allocation schemes, when the macrocell has employed FFR or SFR as its frequency reuse technique. The performance of these schemes is quantified using both the analytical and simulation results for characterizing both the coverage probability and the capacity of D2D links under the proposed schemes that are benchmarked against the radical unity frequency reuse scheme. The impact of the D2D links on the coverage probability of macrocellular users (CUs) is also quantified, revealing that the CUs performance is only modestly affected under the proposed frequency allocation schemes. Finally, we provide insights concerning the power control design in order to strike a beneficial tradeoff between the energy consumption and the performance of D2D lin
Limited Feedback Scheme for Device to Device Communications in 5G cellular networks with Reliability and Cellular Secrecy Outage Constraints
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.Comment: IEEE Transactions on Vehicular Technology, 201