QoS-Aware Joint Mode Selection and Channel Assignment for D2D Communications

TL;DR

This paper proposes a joint mode selection and channel assignment approach for D2D communications in 5G, allowing multiple D2D links per channel while guaranteeing QoS, and introduces algorithms with improved efficiency over exhaustive search.

Contribution

It introduces a joint optimization framework for mode selection and channel assignment in D2D networks, allowing multiple links per channel and ensuring QoS, with efficient algorithms.

Findings

Allowing multiple D2D links per channel improves spectral efficiency.

The proposed algorithms outperform exhaustive search in complexity.

Simulation confirms the effectiveness of joint optimization in dense networks.

Abstract

Underlaying device-to-device (D2D) communications to a cellular network is considered as a key technique to improve spectral efficiency in 5G networks. For such D2D systems, mode selection and resource allocation have been widely utilized for managing interference. However, previous works allowed at most one D2D link to access the same channel, while mode selection and resource allocation are typically separately designed. In this paper, we jointly optimize the mode selection and channel assignment in a cellular network with underlaying D2D communications, where multiple D2D links may share the same channel. Meanwhile, the QoS requirements for both cellular and D2D links are guaranteed, in terms of Signal-to-Interference-plus-Noise Ratio (SINR). We first propose an optimal dynamic programming (DP) algorithm, which provides a much lower computation complexity compared to exhaustive search and serves as the performance bench mark. A bipartite graph based greedy algorithm is then proposed to achieve a polynomial time complexity. Simulation results will demonstrate the advantage of allowing each channel to be accessed by multiple D2D links in dense D2D networks, as well as, the effectiveness of the proposed algorithms.