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In this paper, a user capacity model, combining both the modulation and coding scheme (MCS) distribution model and resource allocation model, is developed to analyze the system performance of wireless communication systems. From the model, we can intuitively calculate the system capacity from MCS distribution. An example based on relay networks is used to quantify the benefit of deploying relay stations.
WiMAX is a broadband wireless technology that supports fixed, nomadic, portable and mobile access. For the fixed or portable applications, the channel can be considered as a static. In this paper, we propose to use channel prediction in order to improve the performances of resource allocation algorithms, in term of outage probability and average throughput. Moreover, for a dynamic OFDMA system, when...
Node cooperation has been demonstrated promising in ameliorating system performance for wireless networks. To effectively and efficiently provision quality-of-service (QoS) at the packet level in wireless mesh networks (WMNs) supporting heterogeneous traffic, medium access control (MAC)-layer resource allocation and service differentiation are imperative. In this paper, we propose a low-complexity...
In wireless multi-hop networks, when an end host would like to communicate with external wired hosts, data packets are to be transmitted at first to a gateway node which is connected to both a wireless multi-hop network and a wired network. When there are multiple candidate gateways to be connected, a wireless host should select one gateway as its own default gateway. One possible and simple way is...
After relaying technology is introduced into the cellular system, many research fields emerge. Among them, resource allocation strategy for distributed and centralized scheduling is an important topic. This paper analyzes and compares the differences between these two scheduling modes, including both system performance and signaling overhead. Two practical scheduling strategies and an efficient routing...
A linear model for evaluating the performance of adaptive resource allocation and user scheduling regarding a single-cell downlink SISO-OFDMA packet data network like LTE is developed in this paper. Based on this model several power, bit, frequency block and frame allocation approaches are examined and the corresponding performance upper bounds are numerically extracted. We put a special emphasis...
User scheduling in future cellular networks is a complex and much-studied problem, further complicated in the increasingly relevant scenario of delay-sensitive VoIP applications. In such cases, the full buffer model that attempts to maximise the total sum-rate of the individual users does not adequately capture the satisfaction level of the users. As a result, fairness needs to be introduced and this...
A new resource allocation scheme for cooperative transmission over multiuser OFDM networks is proposed in this paper. It is assumed that each user has the ability to relay information for others to improve the overall system performance, operating in decode-and-forward (DF) mode. Sub-carriers and power are allocated to users to maximize the uplink system throughput under the constraints of half-duplex,...
Orthogonal frequency division multiple access (OFDMA), which is known as one of the most promising physical techniques for advanced wireless communications system, generally has a guard interval (GI) to mitigate the inter-symbol interference (ISI) and inter-carrier interference (ICI) caused by delay paths. However, the intra-cell interference (ISI and ICI) may be severe, when GI becomes insufficient...
Providing quality of service in broadband wireless access systems is an important issue. Fair throughput scheduling is one scheduling algorithm that is able to guarantee equal throughput in the long term for all users within one cell by allocating a resource to the user with the lowest throughput averaged over a past interval. The throughput that can be obtained by a user depends on the signal to...
In this paper, resource allocation for Orthogonal Frequency Division Multiple Access (OFDMA)-based Wireless Mesh Networks (WMNs) is investigated. First, the Even-Odd framework is modified to be better suited for different traffic patterns. Second, the scheduling problem in the modified Even-Odd framework is formulated as a Mixed Integer Quadratically Constrainted Programming (MIQCP), and a heuristic...
This paper presents a resource allocation framework for the transmission of heterogeneous services in two-hop orthogonal frequency division multiplexing (OFDM) cooperative relay systems. An optimal adaptive power and subcarrier allocation scheme is proposed to maximize the system throughput while satisfying the quality of service (QoS) requirements of both the real-time (RT) and nonreal-time (NRT)...
Cooperative communication in multi-user orthogonal frequency division multiplexing (MU-OFDM) networks is a promising solution to combat wireless channel fading and to increase system throughput. In this paper, with the instantaneous channel state information (CSI) available at base station, the optimal resource allocation strategy is considered in MU-OFDM networks, which is to maximize throughput...
In this paper, we consider a wireless communication network for both low-speed mobile nodes in densely populated hotspots and high-speed mobile nodes roaming in a large area. Wireless local area networks (WLANs) are deployed in the hotspots, while a delay/disruption tolerant network (DTN) provides services to roaming nodes in the large area with low node density. We investigate radio resource allocation...
Informing users about new resource assignments has to be broadcast, thus generating a substantial amount of the mapping overhead that influences the system throughput. In particular, the performance of voice-over-Internet protocol (VoIP) services is seriously affected by the mapping overhead because the VoIP packet size is small. In order to reduce the mapping overhead, a semi-fixed mapping scheme...
An adaptive resource allocation scheme is proposed for regenerative relay-based orthogonal frequency division multiplexing access systems. This scheme allocates subchannels to guarantee fairness between users, and also saves energy by minimising the transmission power. The subchannel allocation for data rate fairness is considered between direct link users and relay stations in the first time subslot...
Uplink scheduling in LTE systems is considered. Two low complexity heuristic algorithms for suboptimal subcarrier allocation are proposed and compared to other algorithms in the literature. Throughput and fairness analysis of the different algorithms are performed via Monte-Carlo simulations. The proposed algorithms are utility maximizing algorithms that can be used with various utility functions...
Optimal power allocation for multi-user amplify- and-forward wireless relay networks in which multiple source-destination pairs are assisted by a set of relays is investigated. Two relay power allocation strategies based on maximization of either i) the minimum rate among all users or ii) the weighted sum of rates are developed. A distributed implementation of the maximum weighted-sum-rate power allocation...
Over the past few decades, unprecedented growth in wireless communications, networking and video-coding technologies have stimulate numerous applications such as video on demand and interactive video telephony. Ultrawideband technology (UWB) which offers high data rate with low transmit power, becomes a very promising wireless platform for video transmission. Recently, cognitive radio (CR) technology...
We study the problem of achieving proportional fair resource allocation in a non-cooperative multiuser OFDM network. We propose an auction-based scheduling algorithm, which combines the merits of the VCG auction and the greedy MC PF algorithm, to ensure that wireless users truthfully declare their resource requirements even though the users are inherently selfish. Through simulations, we find that...
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