The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Fractional frequency reuse (FFR) is an efficient management technique to eliminate inter-cell interference (ICI) in multi-cell orthogonal frequency division multiple access (OFDMA) networks through inter-cell coordination. Generally, the derivations of throughput and coverage probability are treated as separate problems or investigated in different ways. In this paper, we derive average cell throughput...
Consider a 2x2 Gaussian interference channel system in a frequency flat environment. We aim to derive sufficient conditions under which frequency division multiple access (FDMA) is optimal, in the objective of sum-rate maximization under power budget constraints of individual users. Two types of conditions are obtained. Briefly, the former one states that the normalized interference channel gain has...
This paper analyzes the transmission capacity of D2D (Device-to-Device) network in cellular and D2D heterogeneous networks(HetNets) with cellular users (CeUEs) assisted. The D2D network capacity can be enhanced by allocating a part of CeUE transmission power to assist D2D communication. By utilizing stochastic geometry, we first model the HetNets by homogeneous Poisson point process (HPPP). Secondly,...
Device-to-Device (D2D) communication is the technology enabling user equipment (UE) to directly communicate with each other without help of evolved nodeB (eNB) which caters to the demand for high spectrum efficiency. This work focuses on the hybrid network which contains multiple Cellular UEs and D2D UEs. D2D communication shares up-link resource with cellular system and improves the performance of...
Device-to-Device (D2D) communication is an important complement for the future cellular network, which caters to the requirements of mobile internet applications. This article has studied the D2D communication underlaying the cellular networks, which allows the D2D user sharing uplink resource of cellular system. In order to limit mutual interference between cellular links and local D2D links, a semi-autonomous...
A resource allocation scheme involving several Device-to-Device (D2D) multicast groups underlaying OFDMA-based systems is proposed in this paper. In order to guarantee Quality of service (QoS) of cellular users (CeUEs), we define the signal-to-interference-pulse noise ratio (SINR) threshold value for CeUEs. Meanwhile, the minimum throughput of a single D2D multicast group is predetermined to maintain...
Cognitive relay networks have been studied for the advantages of improving the throughput of secondary users. Relay location and power allocation are the key issues in cognitive relay networks, which impact on the system performance. In this paper, we analyze the problem of optimal relay location and power allocation in cognitive relay networks. Firstly, we deduce an ergodic capacity formula for the...
Device-to-Device communication enables high-speed services in the traditional cellular networks but brings potentially mutual interference. In this paper, the heterogeneous network of D2D and IMT-Advanced in a single cell is considered, where the D2D communication is assumed to share the uplink resource with cellular user. The definition of mode selection is first introduced and then a novel distance-dependent...
This paper analyzes the optimal resource allocation for multi-D2D(Device-to-Device) links underlying OFDMA-based networks with the target of reaching maximum sum-throughput of D2D transmission. In order to guarantee QoS (Quality of Service) of cellular users, the rate loss of cellular users is limited by a lower-bound constraint RLC. Meanwhile, the D2D link is allowed to use a sub-carrier only when...
It is expected that Device-to-Device (D2D) communication is allowed to underlay future cellular networks such as IMT-Advanced for spectrum efficiency. However, by reusing the uplink spectrums with the cellular system, the interference to D2D users has to be addressed to maximize the overall system performance. In this paper, a novel method to deal with the resource allocation and interference avoidance...
A hybrid system consisting of a cellular network and a device-to-device (D2D) network is considered in this paper where the D2D users operate in an underlay mode and reuse the spectrums with the cellular users. Most researches focus on reusing the uplink spectrums but how to share the downlink frequency bands is seldom addressed. To share the downlink spectrums and avoid the interference to the primary...
Cognitive radio makes it possible for an unlicensed user to access a licensed spectrum opportunistically on the basis of non-interfering. This paper addresses the problem of joint route selection and resource allocation in OFDMA-based multihop cognitive radio networks, in the objective of optimizing different types of end-to-end performance. Aiming to solve it optimally, we first show that this problem...
A hybrid system of cellular mode and device-to-device (D2D) mode is considered in this paper, where the cellular uplink resource is reused by the D2D transmission. In order to maximize the overall system performance, the mutual interference between cellular and D2D sub-systems has to be addressed. Here, two mechanisms are proposed to solve the problem: One is mitigating the interference from cellular...
Cognitive radio makes it possible for an unlicensed user to access a licensed spectrum opportunistically on the basis of non-interfering. This paper addresses the problem of resource allocation for multiaccess channel (MAC) of OFDMA-based cognitive radio networks, taking into account of the interference temperature constraints. The objective is to maximize the system utility, which is used to quantify...
Cognitive radio and OFDMA attracts a lot of attentions in academic and industry fields. In this paper, the asymptotic performance of an uplink radio resource allocation scheme is investigated for OFDMA-based cognitive radio networks. Considering the characteristics of cognitive radio and OFDMA, in the uplink subcarrier allocation algorithm, the subcarriers are allocated to the users with the best...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.