M. Alasti

University of North Carolina at Charlotte, Charlotte, NC, United States

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Publications (7)4 Total impact

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    ABSTRACT: In this brief, data-rate assignment in IS-856 uplink (reverse link) is studied. The problem is first formulated using an interference model, and then a dynamic control strategy is devel-oped for efficient rate assignment. In the first step, the controller is designed for the special case when the number of users in the network is fixed. Then, the designed controller is further devel-oped for a dynamic network (where the number of users is sub-ject to change) to achieve the desired performance. To this end, the network is formulated in the framework of switched systems, where any new activation or deactivation of users is considered as switching from one system to another. The controllers obtained are then modified properly to retain network stability and perfor-mance in the presence of time-delay. Simulation results are pre-sented to elucidate the effectiveness of the proposed approach.
    IEEE Transactions on Control Systems Technology 03/2013; 21. · 2.00 Impact Factor
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    [Show abstract] [Hide abstract]
    ABSTRACT: In this brief, data-rate assignment in IS-856 uplink (reverse link) is studied. The problem is first formulated using an interference model, and then a dynamic control strategy is devel-oped for efficient rate assignment. In the first step, the controller is designed for the special case when the number of users in the network is fixed. Then, the designed controller is further devel-oped for a dynamic network (where the number of users is sub-ject to change) to achieve the desired performance. To this end, the network is formulated in the framework of switched systems, where any new activation or deactivation of users is considered as switching from one system to another. The controllers obtained are then modified properly to retain network stability and perfor-mance in the presence of time-delay. Simulation results are pre-sented to elucidate the effectiveness of the proposed approach.
    · 2.00 Impact Factor
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    ABSTRACT: In this paper, the problem of resource allocation in IS-856 uplink in the presence of time-delay is studied. A set of nonlinear adaptive controllers are designed to stabilize the wireless network and use the system resources efficiently. The controllers obtained are then modified properly to retain network stability and performance in the presence of time-delay. Simulation results are presented to show the effectiveness of the proposed approach.
    Global Telecommunications Conference, 2009. GLOBECOM 2009. IEEE; 01/2010
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    ABSTRACT: In this paper, the problem of rate allocation in IS-856 uplink is investigated, using a control theoretic approach. An adaptive control scheme is used to stabilize the wireless network and achieve interference regulation. The system stability and output performance are studied in the case of non-fully buffered users for a dynamic network, in the framework of switched systems. Simulation results confirm the effectiveness of the proposed technique.
    Proceedings of the 49th IEEE Conference on Decision and Control, CDC 2010, December 15-17, 2010, Atlanta, Georgia, USA; 01/2010
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    ABSTRACT: In this paper, data-rate assignment in IS-856 uplink (reverse link) is studied. The problem is first formulated in an interference model framework, and then a dynamic control strategy is developed for efficient rate assignment. In the first step, the controller is designed for the special case when the number of users in the network is fixed. Then, the minimum time required for a dynamic network (where the number of users is subject to change) to achieve a desired performance is obtained. The simulation results are presented to elucidate the effectiveness of the proposed approach.
    Communications, 2009. ICC '09. IEEE International Conference on; 07/2009
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    ABSTRACT: Power control is a key air-interface management mechanism for any multiple-access CDMA-based wireless air-interface. Typically it has been used to ensure a target packet-error-rate (PER) for any user connection. In the presence of hybrid-ARQ (HARQ) on the reverse link (as in 3GPP2's EVDO-Rev A), there is additional flexibility that a power control implementation can utilize to ensure quality-of-service (QoS) for any connection. This paper discusses a general framework in which this can be done. It further provides an easily implement able algorithm within this framework, and substantiates its efficacy with simulations.
    Vehicular Technology Conference, 2007. VTC2007-Spring. IEEE 65th; 05/2007
  • H. Alasti, A.G. Aghdam, M. Alasti
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    ABSTRACT: This paper presents an optimal rate assignment mechanism for multimedia transmission over time-varying channels (e.g., the down-link of wireless network IS856 - cdma2000 1timesEv-DO). The proposed method allocates the resources optimally to maximize the delivered quality of service (QoS), which is measured by the average delivered distortion. This optimal mechanism assumes that the scheme used to encode and decode the multimedia information has the embedded property; besides, it assumes that scheduler knows the instantaneous air-link capacities. By taking advantage of the embedded property of the encoding scheme, the proposed optimal rate assignment mechanism adapts the source encoder's rate dynamically, based on its air-link capacity, to deliver the best possible quality of service. As a result, the wireless network (e.g., IS856) can utilize its resources more efficiently, and thus, it can accommodate a higher number of multimedia sessions. Simulation results show that by using the proposed rate assignment a gain of up to 100% in system capacity can be achieved
    Decision and Control, 2006 45th IEEE Conference on; 01/2007