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We consider the problem of resource allocation in downlink OFDMA systems for multi service and unknown environment. Due to users' mobility and intercell interference, the base station cannot predict neither the Signal to Noise Ratio (SNR) of each user in future time slots nor their probability distribution functions. In addition, the traffic is bursty in general with unknown arrival. The probability...
We study in this paper the resource allocation matter for unlicensed multiband ultra-wideband (UWB) users in the context of high-rate wireless personal area network (WPAN). The problem is viewed as a coexistence problem with existing licensed systems. The QoS support and the interference mitigation are jointly considered in this study to derive a novel interference power control mechanism that differentiates...
This paper proposes a novel admission control (AC) algorithm for guaranteed quality of service (QoS) to all users. The proposed solution provides better utilization of system capacity using adaptive modulation (AM). A scheduler based on a per user priority function is also given in this paper. The AC is given by allocating the exact number of slots for each user that will meet its QoS. For every new...
This paper considered multiuser orthogonal frequency multiple access (OFDMA) scheme, which has been proposed as the transmission technique for 4th Generation (4G) cellular network. An optimum and dynamic radio resource (subcarrier and power) allocation scheme is proposed for OFDMA multiuser system. The proposed algorithm has considered a structured degree of flexibility among the services that can...
Block diagonalization is a linear precoding technique which eliminates the multi-user interference at the transmitter side by creating parallel orthogonal single user links. In this technique, the transmit diversity order is fixed for each user and only power can be controlled to satisfy SINR requirements. This restricts the degrees of freedom available for resource allocation and limits the energy...
Cognitive wireless mesh networks have great potential to green communication. One of the critical challenges for realizing such networks is how to adaptively match transmit powers and allocate frequency resources among secondary users of the licensed frequency bands whilst maintaining the quality-of-service (QoS) requirement of the primary users, even in mutually entangled interferences environment...
In this paper, we compare the performance attained by several scheduling policies when the resource allocation is performed in a per-user or in a per-frequency resource ordering. We test the capability of both approaches to deal with the quality of service (QoS) provisioning in a multi-service scenario in a mobile OFDMA network. We probe that the comparative performance of these two approaches depends...
Dynamic spectrum access in cognitive radio (CR) networks is emerging concept to utilize the scarce spectrum in an efficient manner. CR systems will operate in heterogeneous networks in which efficient use of resources will require control of both transmission rate and power for active CRs. In this paper we propose an algorithm for resource allocation in dynamic spectrum access ad-hoc networks where...
Since the using of OFDM in LTE system eliminates the inter-channel interference within cells, inter-cell interference has become the major influence factor of inter-cell resource allocation. Besides, with the increase of types of traffics, different QoS should be provided for different quality of services. A modified algorithm is proposed to ensure multi-traffic QoS by using rate conversion in allocation...
This paper focuses on the adaptive resource allocation strategies for two-hop multiuser OFDMA nonregenerative relay networks considering both maximization of total throughput and fairness constraints among users. First, an optimal resource allocation scheme to maximize the overall data rate is developed with separate transmit power constraints both at source and relay nodes. An alternative scheme...
This paper extends the discrete Verhulst power equilibrium method, previously suggested in to the power-rate optimal allocation problem. Multirate users associated with different types of traffic are aggregated to distinct user' classes, with the assurance of target rate allocation per user and QoS. Therein, single-rate Verhulst power allocation algorithm was adapted to the multirate DS/CDMA power...
Long term evolution (LTE) is the next generation wireless system that supports all IP transmission for multimedia services. The quality of service (QoS) requirements of multimedia services are one of the major challenges that need to be addressed by packet scheduling in the LTE system. This paper proposes a new resource allocation technique for real time (RT) video streaming applications in the downlink...
The primary-secondary user combined power allocation problem is considered in this paper. The problem is addressed in cognitive radio-based relay-assisted networks, where the primary user and the secondary user coexist and influent on each other, and the relays are expected to undertake partial tasks of collecting channel information, computing the optimal power allocation strategy, and informing...
This paper presents a novel fair scheme for resource sharing between nodes in OFDMA mesh networks. The problem is to maximize the overall system rate, under each user's maximal power and minimum rate constraints. To solve the underlying problem, we propose an approach that combines the merits of the well known Lagrange dual framework and the Lambert-W function. By using the Lambert-W function, resource...
This paper proposes a game-theoretic approach to the problem of resource allocation for a CDMA wireless communication network, focusing on code synchronization. To capture the tradeoff between obtaining good synchronization performance and saving as much energy as possible, we propose a noncooperative game in which each pair transmitter-receiver in the network seeks to maximize the ratio of the probability...
This paper studies the performance and coverage improvements introduced by relay deployment in LTE-Advanced systems. Different relay deployment strategies are investigated, namely, amplify-and-forward (AF) repeaters and decode-and-forward (DF) relays (orthogonal and non-orthogonal modes). First, the expressions of peak throughput (i.e., assuming allocate all resources in a cell to one user) for different...
This paper addresses the issue of wireless resource allocation of a Mobile WiMAX cell based on OFDMA access technique. We compare two strategies: the MAX SNR which is the most used channel assignment technique and our proposal which is based on channel condition learning. As we distinguish four IEEE 802.16e-2005 service classes: UGS, rtPS, nrtPS and ErtPS, we combine these strategies with a scheduler...
A novel cross-layer wireless resource allocation scheme is proposed for Orthogonal Frequency Division Multiplex Access (OFDMA) system based on IEEE 802.16e Wireless MAN. With the assumption of a finite queue model, a distinct scheduling priority is defined for each user integrates MAC QoS requirements, queue status and PHY Channel State Information (CSI). Using these scheduling priorities, a scheduling...
In this paper, we investigate the optimization problem of resource allocation in downlink of multiuser MISO-OFDM system. Multiple users with different BER and minimum transmission rate requirements are considered. We propose a novel heuristic allocation algorithm (HAA) of radio resource, which minimizes the total transmit power of the base station while meeting individual users'QoS requirements. The...
In modern wireless communication systems, scheduling and resource allocation are two closely related tasks of the medium access control (MAC) and physical (PHY) layers respectively. In this paper, we present a separate yet interactive design of the two functional modules, where the scheduler prioritizes data packets from different service flows according to their traffic characteristics and feedback...
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