On Coverage Probabilities and Sum-Rate of Full-Duplex Device-to-Device Cellular Networks

Abstract

This paper utilizes the tools of stochastic geometry to derive closed-form approximations of coverage probabilities for both cellular and D2D links of a realistic underlaid full-duplex (FD) cellular D2D network. In the considered model, D2D users operate in FD mode under the adverse effect of realistic residual self-interference, and their locations are modeled by a homogeneous spatial Poison point process (PPP). The coverage probabilities involve multiple integrals due to the average over the distributions of transmit power, wireless fading, and link distances. Therefore, our solution is to first apply Laplace transforms and novel approximations that accurately approximate the expected values of fractional and exponential functions of random variables to obtain the distributions of signal to interference and noise ratios (SINRs) at the base station (BS) and D2D users. By further taking the average over the distributions of cellular and D2D link distances, we then arrive at the closed-form approximations of cellular and D2D coverage probabilities. Furthermore, based on the approximation of D2D link coverage probability, an analytical expression of the D2D link sum-rate is obtained, which can be effectively calculated. Our results show that the integration of FD in D2D provides significant sum-rate improvement over the half-duplex D2D counterpart.