Resource Allocation for Device-to-Device Communications Underlaying Heterogeneous Cellular Networks Using Coalitional Games

Heterogeneous cellular networks (HCNs) with millimeter wave (mmWave) communications included are emerging as a promising candidate for the fifth generation mobile network. With highly directional antenna arrays, mmWave links are able to provide several-Gbps transmission rate. However, mmWave links are easily blocked without line of sight. On the other hand, D2D communications have been proposed to support many content based applications, and need to share resources with users in HCNs to improve spectral reuse and enhance system capacity. Consequently, an efficient resource allocation scheme for D2D pairs among both mmWave and the cellular carrier band is needed. In this paper, we first formulate the problem of the resource allocation among mmWave and the cellular band for multiple D2D pairs from the view point of game theory. Then, with the characteristics of cellular and mmWave communications considered, we propose a coalition formation game to maximize the system sum rate in statistical average sense. We also theoretically prove that our proposed game converges to a Nash-stable equilibrium and further reaches the near-optimal solution with fast convergence rate. Through extensive simulations under various system parameters, we demonstrate the superior performance of our scheme in terms of the system sum rate compared with several other practical schemes.Comment: 13 pages, 12 figure

Interference Management using Power Control for Device-to-Device Communication in Future Cellular Network, Journal of Telecommunications and Information Technology, 2018, nr 3

There are many scenarios that have been proposed for fifth generation (5G) networks. Some of them, if implemented, will bring fundamental changes at the architectural and node level. One example of such proposed technologies is device-to-device (D2D) communications which will change the nature of conventional cellular network design. D2D permits direct communication between two or more user devices without intervention of the base station (i.e. eNB). D2D can ensure network performance improvement over the traditional cellular network, because it can offload the mobile data traffic from the other devices. However, applying D2D features in a cellular network will bring about more complex interference problems, since D2D communication uses the same band as its underlying cellular communication network. The aim of this research is to investigate interference-related problems caused by D2D communications, affecting the underlying cellular networks, during downlink and uplink transmissions. The paper examines the use of power control methods to mitigate interference. A comparison is offered between fixed power level (FC) with or without power control, and adaptive power controls using two methods (AC1 and AC2), on a base station or on each of the D2D devices, based on the measured signal to interference plus noise ratio (SINR). The simulation results show that both power control methods contribute to improvement of network performance. AC1 and AC2 can improve SINR by about 1 dB and 0.5 dB compared to FC in a downlink transmission, and by 0.5 dB in an uplink transmission

Interferência em comunicações Device-to-Device D2D

A constante necessidade de aumento da capacidade de rede para atender às crescentes demandas dos assinantes, leva a indústria de telecomunicações, apoiada pela comunidade científica, a criar novos paradigmas que suportem requisitos de taxa de dados binários elevados dentro da rede de acesso sem fio existente de forma eficiente e eficaz. Para responder a este desafio, a Comunicação Device-to-Device (D2D) em redes celulares é vista como uma solução promissora. Deste modo, a presente dissertação consiste na exploração do modelo de comunicação D2D (Device-to-Device), mediante o desenvolvimento de várias rotinas de comunicação D2D dentro de uma estrutura de rede celular LTE-A, usando simuladores já existentes, nomeadamente, simuladores de sistema em JAVA e simuladores de ligação em MatLab, afim de analisar o eventual aumento de capacidade da comunicação D2D para rede celular. Tipicamente, as comunicações em D2D permitem que os utilizadores localizados na proximidade, possam comunicar diretamente sem a intervenção da estação base (BS - Base Station). Essa comunicação pode permitir ritmos binários muito elevados, baixos atrasos e poupança de energia. Nesta dissertação alterou-se o simulador de sistema celular existente para incluir as comunicações D2D e as suas interferências, sendo apresentados os resultados obtidos. Os resultados obtidos por simulação confirmaram o que se esperava, nomeadamente, aumento dos ritmos binários nas comunicações D2D e redução do atraso.The continuing need to increase network capacity to meet growing subscriber demands leads the telecommunications industry, backed by the scientific community, to create new paradigms that support high binary data rate requirements within the existing wireless access network efficiently and effectively. To meet this challenge, Device-toDevice (D2D) Communication in cellular networks is seen as a promising solution. Thus, the present dissertation consists of the exploitation of the D2D (Device-toDevice) communication model, by developing several D2D communication routines within a LTE-A cellular network structure, using existing simulators, namely, simulator of system in JAVA and simulator of link in MatLab, in order to analyze the possible increase of capacity of D2D communication for cellular network. Typically, D2D communications allow users located in close proximity to communicate directly without the intervention of the base station (BS - Base Station). This communication can allow very high binary rates, low delays and energy savings. In this dissertation, the existing cellular system simulator was modified to include D2D communications and their interference, and the results obtained were presented. Simulation results have confirmed what was expected, namely, increasing bit rate with D2D communications and lower delays

Journal of Telecommunications and Information Technology, 2018, nr 3

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