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Cooperative relaying is a promising technique for present wireless communication networks such as Orthogonal Frequency Division Multiple Access (OFDMA) to satisfy high throughput demand andquality-of-service (QoS) requirements. A suboptimal relay selection, power allocation and sub carrier assignment scheme under a total power constraint is proposed for a QoS aware resource allocation for a cooperative...
In Wireless Mesh Networks (WMNs), supporting Quality of Service (QoS) to enable a rich portfolio of applications/real-time multimedia applications is foreseen to be vital for the success of next generation networking technologies. However, today's cutting edge standards are not perfectly equipped to cater to this task. These standards come with an inherent complexity and suffer from innate problems...
In 4G cellular networks: LTE/LTE-Advanced and the mobile WiMAX network, some key impact factors degrade signal transmission quality and reduce wireless service coverage significantly. The specifications of LTE-Advanced and IEEE 802.16j thus propose a relay-based scheme, namely Mobile Multihop Relay (MMR) networks, to cooperate with the existing cellular network and to guarantee QoS for requests while...
In this paper, we propose relay transmission protocol based on SoQ(Satisfaction of QoS) for QoS enhancement and analyze the performance of the proposed method in Wireless USB Networks. In the proposed protocol, Wireless USB host executes the Satisfaction of QoS (SoQ) time slot allocation algorithm. And, in order to give devices with scarce resource another chance to improve QoS, the proposed relay...
This paper studies the resource allocation problem in orthogonal frequency division multiple access (OFDMA) cooperative relaying cellular systems. Most existing work on resource allocation does not fully consider all the influential factors for such systems. In the paper, we formulate the optimization problem for resource allocation, including relay selection, subcarrier assignment, and power allocation...
In mobile Ad-hoc networks forwarding data through intermediate relays extends the coverage area and enhances the network throughput. Dynamic assignment of routes for data transmission from sources to destinations that is optimized based on channel conditions in a cross-layer manner could provide improved performance. We consider a general multiuser two-hop transmission, where each flow is subject...
Vehicular networks are highly mobile wireless networks that can provide wide variety of services and applications such as public safety communications, crash avoidance, multimedia and Internet access in highways. Designing routing algorithm in vehicular network is a challenging task due to rapidly changing topology and high speed mobility of vehicles. One of the critical issues of vehicular network...
This paper investigates the power allocation algorithms based on convex theory for multiuser multi-relay amplify-and-forward (AAF) wireless cooperative network. In this system, there are multiple single-antenna users to communicate with one destination with the help of multiple relay nodes at the same time. In order to guarantee the quality-of-service (QoS) for all the users and reduce the power consumption,...
We study the power allocation algorithms in the case of multi-source multi-relay (MSMR) amplify-and-forward wireless cooperative network in this paper. In this MRMS system, we consider that multiple users would communicate with one destination node with the help of multiple relay nodes in the same time. To guarantee the quality-of-service (QoS) for all the users and reduce the power consumption, we...
We investigate fundamental characteristics of cooperative transmission in terms of power efficiency. By introducing the concept of “cooperative region”, we evaluate the average power efficiency which is defined as the ratio of total consumed transmit power with cooperation to that of direct transmission and show how the average performance depends upon the QoS requirement, distance between source...
This paper investigated the admission control problem in multi-service cellular relay system with orthogonal frequency division multiplexing access (OFDMA). Subjected to a hard constraint on the quality-of-service (QoS) requirements and the capability of relay, the admission problem could be described as the problem of maximizing the amount of subcarriers saved by relaying transmission. With further...
In this paper, heterogeneous services in multiuser multiple-input multiple-output (MIMO)-Relay systems are investigated, where the relays work in amplify-and-forward mode. A utility based adaptive scheduling algorithm is proposed, which aims to maximize user satisfaction as well as system spectral efficiency. Joint optimal carriers and spatial subchannels allocation is considered based on the proposed...
An adaptive resource assignment scheme for the multi-user cooperative communication systems with amplify-and-forward (AF) relays is investigated. We consider maximizing system capacity while guaranteeing the QoS (Quality of Service) of each user. A resource assignment is proposed using space-time coding with only source-to-relay channel gain information (CGI). It performs well in allocating relay...
An adaptive relay allocation scheme for multi-user cooperative communication systems with amplify-and-forward (AF) relays is investigated. We consider maximizing system capacity while guaranteeing the QoS (Quality of Service) of each user. Proposed relay allocation scheme uses space-time coding technique. It performs well in allocating relay nodes to multiple source-destination pairs. The proposed...
For supporting the high quality of service (QoS) in relay network, this paper proposes a new scheduling scheme that can be adopted in the orthogonal frequency division multiple access (OFDMA) cellular systems. In relay-aided network, a relay station should receive data from base station for forwarding data to its serving mobile stations. In addition, since the channel quality of each hop cannot be...
The large number of network nodes and the energy constraints make the field of wireless networks, especially ad-hoc network one of the most important application fields for cooperative diversity. In this paper we presents a new architecture based on the principle of cooperation between the terminals, in which MIMO technology is virtually introduced to transmit information, taking benefit from the...
Relay selection is a challenging issue in cooperative communication networks. In particular, in a multi-user multi- concurrent-transmission network, effects of the resource sharing of a relay by its served users on the relay selection strategy need to be taken into account. There is little research on this investigation in literature. In this paper, we propose a novel efficient and fair relay selection...
In this letter we investigate the placement of nodes, based on their residual energies, when both the forward and the backward directions of a data flow are considered. First we extend the monodirectional flow model and determine the nodes' positions that achieve the longest path-lifetime, then we propose a new model that allows us to find the optimal placement depending on the quota of energy that...
Being an evolution of IEEE 802.16e, IEEE 802.16J mobile multi-hop relay (MMR) is proposed to gain coverage extension and throughput enhancement. The new network architecture imposes a demanding performance requirement on relay stations (RS), and these RSs involve great signaling overhead and latency compares with non-RS network. This article proposes a new method that manages service flows in 802...
In multicast/broadcast services over infrastructure- based/cellular wireless networks (e.g. 3G cellular networks, WiMax, DVB), data is transmitted to multiple recipients from an access point/base station. Multicast greatly improves the network efficiency to distribute data to multiple recipients as compared to multiple unicast sessions of the same data to each receiver individually, by taking advantage...
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