2012 IEEE International Conference on Communication Systems (ICCS), 2012
ABSTRACT We consider the problem of mode selection for device-to-device (D2D) communications in L... more ABSTRACT We consider the problem of mode selection for device-to-device (D2D) communications in LTE-advanced networks. We propose a solution based on a coalitional game among D2D links to select their communications modes. The solution is given by three coalitions which represent the groups of D2D links using cellular mode, reuse mode, and dedicated mode of transmission. The D2D links in the same coalition cooperatively select the subchannels and use the corresponding transmission mode such that the total power is minimized while their rate requirements are satisfied. The D2D links can make a decision to leave and join a coalition based on their individual transmission costs. The individual transmission cost of each D2D link is a function of the transmission power and the price of channel occupancy which depends on the D2D link's communications mode. We find stable coalitions as the solution of the mode selection problem. The stable coalitions represent the system states in which no D2D link can change its communication mode and have lower transmission cost without making others worse off. A discrete-time Markov chain-based analysis and a distributed algorithm are presented to obtain the stable coalitions.
We present a joint resource allocation (RA) and admission control (AC) framework for an orthogona... more We present a joint resource allocation (RA) and admission control (AC) framework for an orthogonal frequency-division multiple access (OFDMA)-based cellular network composed of a macrocell overlaid by small cells. In this framework, the resource allocation problems for both the macrocell and small cells are formulated as optimization problems. The macrocell RA problem is aware of the existence of the small cell tier. On the other hand, the RA and AC problems for the small cells aim at maximizing the number of admitted users while simultaneously minimizing the consumed bandwidth. These optimization problems are shown to be mixed integer nonlinear problems (MINLPs). Techniques are proposed to obtain either the optimal solution or a bound on the optimal solution with reduced complexity through convex relaxation. Dual decomposition technique is also used to have a distributed solution for the small cell tier. Numerical results confirm that the convex relaxations follow a similar behavior to the MINLP formulations. Also, the distributed solution converges to the optimal solution obtained by solving the corresponding convex optimization problem in a centralized fashion.
2012 IEEE International Conference on Communication Systems (ICCS), 2012
ABSTRACT We consider the problem of mode selection for device-to-device (D2D) communications in L... more ABSTRACT We consider the problem of mode selection for device-to-device (D2D) communications in LTE-advanced networks. We propose a solution based on a coalitional game among D2D links to select their communications modes. The solution is given by three coalitions which represent the groups of D2D links using cellular mode, reuse mode, and dedicated mode of transmission. The D2D links in the same coalition cooperatively select the subchannels and use the corresponding transmission mode such that the total power is minimized while their rate requirements are satisfied. The D2D links can make a decision to leave and join a coalition based on their individual transmission costs. The individual transmission cost of each D2D link is a function of the transmission power and the price of channel occupancy which depends on the D2D link's communications mode. We find stable coalitions as the solution of the mode selection problem. The stable coalitions represent the system states in which no D2D link can change its communication mode and have lower transmission cost without making others worse off. A discrete-time Markov chain-based analysis and a distributed algorithm are presented to obtain the stable coalitions.
We present a joint resource allocation (RA) and admission control (AC) framework for an orthogona... more We present a joint resource allocation (RA) and admission control (AC) framework for an orthogonal frequency-division multiple access (OFDMA)-based cellular network composed of a macrocell overlaid by small cells. In this framework, the resource allocation problems for both the macrocell and small cells are formulated as optimization problems. The macrocell RA problem is aware of the existence of the small cell tier. On the other hand, the RA and AC problems for the small cells aim at maximizing the number of admitted users while simultaneously minimizing the consumed bandwidth. These optimization problems are shown to be mixed integer nonlinear problems (MINLPs). Techniques are proposed to obtain either the optimal solution or a bound on the optimal solution with reduced complexity through convex relaxation. Dual decomposition technique is also used to have a distributed solution for the small cell tier. Numerical results confirm that the convex relaxations follow a similar behavior to the MINLP formulations. Also, the distributed solution converges to the optimal solution obtained by solving the corresponding convex optimization problem in a centralized fashion.
Uploads
Papers by Ekram Hossain