The Experts below are selected from a list of 158997 Experts worldwide ranked by ideXlab platform
Rudra Dutta - One of the best experts on this subject based on the ideXlab platform.
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Joint Design
Designing for Network and Service Continuity in Wireless Mesh Networks, 2013Co-Authors: Parth H. Pathak, Rudra DuttaAbstract:Having described individual problems of Design in mesh networks in an earlier chapter, we now describe Design problems that more recent literature has focused on, which address the problem of Jointly Designing more than one functional or operational aspect of the network, such as Joint routing and power control. As before, we survey solution approaches proposed in literature as well as describing the problems. We first organize our discussion by explicit combinations of functions, but later we include discussions on Designing for sustainability in energy, back-pressure related Design, and cognitive mesh Design, since these Design areas (while having their distinct identities) can all be seen as Joint or multifunction Design as we have described here.
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a survey of network Design problems and Joint Design approaches in wireless mesh networks
IEEE Communications Surveys and Tutorials, 2011Co-Authors: Parth H. Pathak, Rudra DuttaAbstract:Over the last decade, the paradigm of Wireless Mesh Networks (WMNs) has matured to a reasonably commonly understood one, and there has been extensive research on various areas related to WMNs such as Design, deployment, protocols, performance, etc. The quantity of research being conducted in the area of wireless mesh Design has dramatically increased in the past few years, due to increasing interest in this paradigm as its potential for the "last few miles", and the possibility of significant wireless services in metropolitan area networks. This recent work has focused increasingly on Joint Design problems, together with studies in Designing specific aspects of the WMN such as routing, power control etc. in isolation. While excellent surveys and tutorials pertaining to WMNs exist in literature, the explosive growth of research in the area of specific Design issues, and especially Joint Design, has left them behind. Our objective in this paper is to identify the fundamental WMN Design problems of interference modeling, power control, topology control, link scheduling, and routing, and provide brief overviews, together with a survey of the recent research on these topics, with special stress on Joint Design methods. We believe this paper will fulfill an outstanding need in informing the interested student and researcher in getting familiar with this abundant recent research area, and starting research.
A Swami - One of the best experts on this subject based on the ideXlab platform.
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Joint Design and separation principle for opportunistic spectrum access in the presence of sensing errors
IEEE Transactions on Information Theory, 2008Co-Authors: Yunxia Chen, Qing Zhao, A SwamiAbstract:Opportunistic spectrum access (OSA) that allows secondary users to independently search for and exploit instantaneous spectrum availability is considered. The Design objective is to maximize the throughput of a secondary user while limiting the probability of colliding with primary users. Integrated in the Joint Design are three basic components: a spectrum sensor that identifies spectrum opportunities, a sensing strategy that determines which channels in the spectrum to sense, and an access strategy that decides whether to access based on potentially erroneous sensing outcomes. This Joint Design is formulated as a constrained partially observable Markov decision process (POMDP), and a separation principle is established. The separation principle reveals the optimality of myopic policies for the Design of the spectrum sensor and the access strategy, leading to closed-form optimal solutions. Furthermore, it decouples the Design of the sensing strategy from that of the spectrum sensor and the access strategy, and reduces the constrained POMDP to an unconstrained one. Numerical examples are provided to study the tradeoff between sensing time and transmission time, the interaction between the physical layer spectrum sensor and the MAC layer sensing and access strategies, and the robustness of the ensuing Design to model mismatch.
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Joint Design and separation principle for opportunistic spectrum access in the presence of sensing errors
arXiv: Networking and Internet Architecture, 2007Co-Authors: Yunxia Chen, Qing Zhao, A SwamiAbstract:We address the Design of opportunistic spectrum access (OSA) strategies that allow secondary users to independently search for and exploit instantaneous spectrum availability. Integrated in the Joint Design are three basic components: a spectrum sensor that identifies spectrum opportunities, a sensing strategy that determines which channels in the spectrum to sense, and an access strategy that decides whether to access based on imperfect sensing outcomes. We formulate the Joint PHY-MAC Design of OSA as a constrained partially observable Markov decision process (POMDP). Constrained POMDPs generally require randomized policies to achieve optimality, which are often intractable. By exploiting the rich structure of the underlying problem, we establish a separation principle for the Joint Design of OSA. This separation principle reveals the optimality of myopic policies for the Design of the spectrum sensor and the access strategy, leading to closed-form optimal solutions. Furthermore, decoupling the Design of the sensing strategy from that of the spectrum sensor and the access strategy, the separation principle reduces the constrained POMDP to an unconstrained one, which admits deterministic optimal policies. Numerical examples are provided to study the Design tradeoffs, the interaction between the spectrum sensor and the sensing and access strategies, and the robustness of the ensuing Design to model mismatch.
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Joint Design and separation principle for opportunistic spectrum access
Asilomar Conference on Signals Systems and Computers, 2006Co-Authors: Yunxia Chen, Qing Zhao, A SwamiAbstract:This paper develops optimal strategy for opportunistic spectrum access (OSA) by integrating the Design of spectrum sensor at the physical layer with that of spectrum sensing and access policies at the medium access control (MAC) layer. The Design objective is to maximize the throughput of secondary users while limiting their probability of colliding with primary users. By exploiting the rich structures of the problem, we establish a separation principle: the Design of spectrum sensor and access policy can be decoupled from that of sensing policy without losing optimality. This separation principle enables us to obtain closed- form optimal sensor operating characteristic and access policy, leading to significant complexity reduction. It also allows us to study the inherent interaction between spectrum sensor and access policy and the tradeoff between false alarm and miss detection in opportunity identification.
Matti Latvaaho - One of the best experts on this subject based on the ideXlab platform.
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Joint Design of tx rx beamformers in mimo downlink channel
IEEE Transactions on Signal Processing, 2007Co-Authors: Marian Codreanu, Antti Tolli, Markku Juntti, Matti LatvaahoAbstract:We consider a single-cell multiple-input multiple-output (MIMO) downlink channel where linear transmission and reception strategy is employed. The base station (BS) transmitter is equipped with a scheduler using a simple opportunistic beamforming strategy, which associates an intended user for each of the transmitted data streams. For the case when the channel of the scheduled users is available at the BS, we propose a general method for Joint Design of the transmit and the receive beamformers according to different optimization criteria, including weighted sum rate maximization, weighted sum mean square error minimization, minimum signal-to-interference-plus-noise ratio (SINR) maximization and sum power minimization under a minimum SINR constraint. The proposed method can handle multiple antennas at the BS and at the mobile user with single and/or multiple data streams per scheduled user. The optimization problems encountered in the beamformer Design (e.g., covariance rank constraint) are not convex in general. Therefore, the problem of finding the global optimum is intrinsically nontractable. However, by exploiting the uplink-downlink SINR duality, we decompose the original optimization problem as a series of simpler optimization problems which can be efficiently solved by using standard convex optimization tools. Even though each subproblem is optimally solved, there is no guarantee that the global optimum has been found due to the nonconvexity of the problem. However, the simulations show that the algorithms converge fast to a solution, which can be a local optimum, but is still efficient.
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Joint Design of tx rx beamformers in mimo downlink channel
International Conference on Communications, 2007Co-Authors: Marian Codreanu, Antti Tolli, Markku Juntti, Matti LatvaahoAbstract:We consider a single-cell multiple-input multiple-output (MIMO) downlink channel where linear transmission and reception strategy is employed. The base station (BS) transmitter is equipped with a scheduler using a simple opportunistic beamforming strategy, which associates an intended user for each of the transmitted data streams. For the case when the channel of the scheduled users is available at the BS, we propose a general method for Joint Design of the transmit and the receive beamformers according to different optimization criteria. The proposed method can handle multiple antennas at the BS and at the mobile user with single and/or multiple data streams per scheduled user. By exploiting the uplink-downlink SINR duality, we decompose the original optimization problem as a series of simpler optimization problems which can be efficiently solved by using standard convex optimization tools. The simulations show that the algorithms converge fast to a solution, which can be a local optimum, but is still efficient. Only one iteration of the proposed method is enough to substantially outperform the zero forcing based solution.
Parth H. Pathak - One of the best experts on this subject based on the ideXlab platform.
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Joint Design
Designing for Network and Service Continuity in Wireless Mesh Networks, 2013Co-Authors: Parth H. Pathak, Rudra DuttaAbstract:Having described individual problems of Design in mesh networks in an earlier chapter, we now describe Design problems that more recent literature has focused on, which address the problem of Jointly Designing more than one functional or operational aspect of the network, such as Joint routing and power control. As before, we survey solution approaches proposed in literature as well as describing the problems. We first organize our discussion by explicit combinations of functions, but later we include discussions on Designing for sustainability in energy, back-pressure related Design, and cognitive mesh Design, since these Design areas (while having their distinct identities) can all be seen as Joint or multifunction Design as we have described here.
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a survey of network Design problems and Joint Design approaches in wireless mesh networks
IEEE Communications Surveys and Tutorials, 2011Co-Authors: Parth H. Pathak, Rudra DuttaAbstract:Over the last decade, the paradigm of Wireless Mesh Networks (WMNs) has matured to a reasonably commonly understood one, and there has been extensive research on various areas related to WMNs such as Design, deployment, protocols, performance, etc. The quantity of research being conducted in the area of wireless mesh Design has dramatically increased in the past few years, due to increasing interest in this paradigm as its potential for the "last few miles", and the possibility of significant wireless services in metropolitan area networks. This recent work has focused increasingly on Joint Design problems, together with studies in Designing specific aspects of the WMN such as routing, power control etc. in isolation. While excellent surveys and tutorials pertaining to WMNs exist in literature, the explosive growth of research in the area of specific Design issues, and especially Joint Design, has left them behind. Our objective in this paper is to identify the fundamental WMN Design problems of interference modeling, power control, topology control, link scheduling, and routing, and provide brief overviews, together with a survey of the recent research on these topics, with special stress on Joint Design methods. We believe this paper will fulfill an outstanding need in informing the interested student and researcher in getting familiar with this abundant recent research area, and starting research.
Yunxia Chen - One of the best experts on this subject based on the ideXlab platform.
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Joint Design and separation principle for opportunistic spectrum access in the presence of sensing errors
IEEE Transactions on Information Theory, 2008Co-Authors: Yunxia Chen, Qing Zhao, A SwamiAbstract:Opportunistic spectrum access (OSA) that allows secondary users to independently search for and exploit instantaneous spectrum availability is considered. The Design objective is to maximize the throughput of a secondary user while limiting the probability of colliding with primary users. Integrated in the Joint Design are three basic components: a spectrum sensor that identifies spectrum opportunities, a sensing strategy that determines which channels in the spectrum to sense, and an access strategy that decides whether to access based on potentially erroneous sensing outcomes. This Joint Design is formulated as a constrained partially observable Markov decision process (POMDP), and a separation principle is established. The separation principle reveals the optimality of myopic policies for the Design of the spectrum sensor and the access strategy, leading to closed-form optimal solutions. Furthermore, it decouples the Design of the sensing strategy from that of the spectrum sensor and the access strategy, and reduces the constrained POMDP to an unconstrained one. Numerical examples are provided to study the tradeoff between sensing time and transmission time, the interaction between the physical layer spectrum sensor and the MAC layer sensing and access strategies, and the robustness of the ensuing Design to model mismatch.
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Joint Design and separation principle for opportunistic spectrum access in the presence of sensing errors
arXiv: Networking and Internet Architecture, 2007Co-Authors: Yunxia Chen, Qing Zhao, A SwamiAbstract:We address the Design of opportunistic spectrum access (OSA) strategies that allow secondary users to independently search for and exploit instantaneous spectrum availability. Integrated in the Joint Design are three basic components: a spectrum sensor that identifies spectrum opportunities, a sensing strategy that determines which channels in the spectrum to sense, and an access strategy that decides whether to access based on imperfect sensing outcomes. We formulate the Joint PHY-MAC Design of OSA as a constrained partially observable Markov decision process (POMDP). Constrained POMDPs generally require randomized policies to achieve optimality, which are often intractable. By exploiting the rich structure of the underlying problem, we establish a separation principle for the Joint Design of OSA. This separation principle reveals the optimality of myopic policies for the Design of the spectrum sensor and the access strategy, leading to closed-form optimal solutions. Furthermore, decoupling the Design of the sensing strategy from that of the spectrum sensor and the access strategy, the separation principle reduces the constrained POMDP to an unconstrained one, which admits deterministic optimal policies. Numerical examples are provided to study the Design tradeoffs, the interaction between the spectrum sensor and the sensing and access strategies, and the robustness of the ensuing Design to model mismatch.
-
Joint Design and separation principle for opportunistic spectrum access
Asilomar Conference on Signals Systems and Computers, 2006Co-Authors: Yunxia Chen, Qing Zhao, A SwamiAbstract:This paper develops optimal strategy for opportunistic spectrum access (OSA) by integrating the Design of spectrum sensor at the physical layer with that of spectrum sensing and access policies at the medium access control (MAC) layer. The Design objective is to maximize the throughput of secondary users while limiting their probability of colliding with primary users. By exploiting the rich structures of the problem, we establish a separation principle: the Design of spectrum sensor and access policy can be decoupled from that of sensing policy without losing optimality. This separation principle enables us to obtain closed- form optimal sensor operating characteristic and access policy, leading to significant complexity reduction. It also allows us to study the inherent interaction between spectrum sensor and access policy and the tradeoff between false alarm and miss detection in opportunity identification.
