Abstract

The sum-rate maximization in a device-to-device (D2D) enabled cellular system is studied in this work. With D2D communication, a closely located user pair can communicate through a direct data link in order to obtain a higher data rate and offload the core network. Short-range D2D links are allowed to share the channels of others in the same cell for better spatial reuse. Over a shared channel, the sum-rate maximization through power control is an intractable non-convex optimization problem. For the case that a channel is shared by at most two users, an optimal and simple transmit power allocation algorithm is proposed. It is derived that the optimal power allocation resides on one out of four points on the Pareto optimal boundary of the feasible signal-to-interference-plus-noise ratio (SINR) region. Then a low-complexity greedy channel assignment algorithm is proposed. Simulation results are provided to demonstrate the efficiency and effectiveness of the proposed algorithms. In addition, it is shown that significant improvement in system throughput is obtained from D2D channel reuse.

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