ABSTRACT in this paper we propose and investigate a cross-layer multiuser scheduling strategy for... more ABSTRACT in this paper we propose and investigate a cross-layer multiuser scheduling strategy for the support of heterogeneous traffic in the downlink of a MIMO-OFDMA system. It jointly considers different objectives: maximize the sum-rate on the radio channel, ensure a fair allocation of resources among users belonging to the same traffic class, consider the dynamics of traffic sources by looking at the delay of data packets in the queues, contribute to maximize quality of service figures at the application level. To exploit temporal diversity and to reduce complexity, the ergodic weighted sum-rate is maximized and dual optimization with stochastic approximation is applied to derive on-line algorithms. The numerical results show the capability of the scheduler to allocate physical layer resources according to rate constraints imposed for each different traffic class and with fairness inside each class, even in presence of different channels conditions and different network loads. Postprint (published version)
Page 1. A LOW COMPLEXITY SPACE-FREQUENCY MULTIUSER SCHEDULING ALGORITHM Ana I. Pérez-Neira1,2, Po... more Page 1. A LOW COMPLEXITY SPACE-FREQUENCY MULTIUSER SCHEDULING ALGORITHM Ana I. Pérez-Neira1,2, Pol Henarejos1, Velio Tralli3, Miguel A. Lagunas1,2 email: [email protected], [email protected], [email protected], [email protected] (1) Dept. ...
ABSTRACT This article describes the implementation of a prototype visible light communications sy... more ABSTRACT This article describes the implementation of a prototype visible light communications system based on the IEEE 802.15.7 standard using lowcost commercial off-the-shelf analog devices. The aim of this article is to show that this standard provides a framework that could promote the introduction of applications into the market. Thus, these specifications could be further developed, reducing the gap between the industry and research communities. The implemented prototype makes use of software defined radio platforms to interface between the analog devices and the computer where the signal processing is performed. The use of this concept provides the system with enough flexibility and modularity to include new features in the prototype without requiring long development time.
ABSTRACT The aim of this paper is to present an implementation of a functional IEEE 802.15.7 real... more ABSTRACT The aim of this paper is to present an implementation of a functional IEEE 802.15.7 real-time testbed based on the Software Defined Radio (SDR) concept. This implementation is built with low cost commercial off-the-shelf (COTS) analog devices and the use of Universal Software Radio Peripheral version 2 (USRP2) equipment combined with a generic object-oriented framework that takes advantage of several open source software libraries. The prototype is validated in a controlled laboratory environment with an over-the-air measurement campaign.
In this paper we present our approach regarding the implementation of new wireless radio receiver... more In this paper we present our approach regarding the implementation of new wireless radio receivers exploiting filterbank techniques, using a software-development driven approach. The fact that most of the common radio communication systems share a similar structure has been exploited to create a framework which provides a generic layout and tools to construct reconfigurable transmitters and/or receivers. By combining our own generic object-oriented framework built on top of the GNU Radio software framework with the use of the Universal Software Radio Peripheral version 2 (USRP2), we have been able to quickly implement a working proof of concept of an Uplink (UL) Filterbank Multicarrier (FBMC) receiver, both for Single-Input Single-Output (SISO) and Multiple-Input Multiple-Output (MIMO) scenario, within the 7th European framework project called PHYDYAS. As well, a description of the methodology we have applied from software engineering in order to build this demonstrator is herein included, which shows the suitability of using Software Defined Radio (SDR) technologies for fast prototyping of new wireless communication systems.
OFDMA systems are considered as the promising multiple access scheme of next generation multi-cel... more OFDMA systems are considered as the promising multiple access scheme of next generation multi-cellular wireless systems. In order to ensure the optimum usage of radio resources, OFDMA radio resource management algorithms have to maximize the allocated power and rate of the different subchannels to the users taking also into account the generated co-channel interference between neighboring cells, which affects the received Quality of Service. This paper discusses various schemes for power distribution schemes in multiple co-channel cells. These schemes include centralized and distributed solutions, which may involve various degrees of complexity and related overhead and may employ procedures such as linear programming. Finally, the paper introduces a new solution that uses a network flow model to solve the maximization of the multi-cell system sum rate. The application of spatial beamforming at each cell is suggested in order to better cope with interference.
ABSTRACT This paper presents a low-complexity algorithm for multiuser scheduling and resource all... more ABSTRACT This paper presents a low-complexity algorithm for multiuser scheduling and resource allocation in the Multiple Input Single Output (MISO) downlink channel with Orthogonal Frequency Division Multiple Access (OFDMA). The goal of the algorithm is to maximize the sum-rate on the radio channel and to ensure that the rate assignment is suitably balanced among users. The proposed algorithm uses partial Channel State Information (CSI) and therefore has a reduced feedback requirement. It also allows an on-line implementation, based on an ergodic optimization framework with dual optimization and stochastic approximation. Performance and complexity reduction are quantified by considering comparison with other solutions in a realistic single-cell system configuration. It is shown that the algorithm is effective to balance average rate among users even in heterogeneous and non-stationary channel conditions with lower computational complexity and feedback requirements.
ABSTRACT in this paper we propose and investigate a cross-layer multiuser scheduling strategy for... more ABSTRACT in this paper we propose and investigate a cross-layer multiuser scheduling strategy for the support of heterogeneous traffic in the downlink of a MIMO-OFDMA system. It jointly considers different objectives: maximize the sum-rate on the radio channel, ensure a fair allocation of resources among users belonging to the same traffic class, consider the dynamics of traffic sources by looking at the delay of data packets in the queues, contribute to maximize quality of service figures at the application level. To exploit temporal diversity and to reduce complexity, the ergodic weighted sum-rate is maximized and dual optimization with stochastic approximation is applied to derive on-line algorithms. The numerical results show the capability of the scheduler to allocate physical layer resources according to rate constraints imposed for each different traffic class and with fairness inside each class, even in presence of different channels conditions and different network loads. Postprint (published version)
Page 1. A LOW COMPLEXITY SPACE-FREQUENCY MULTIUSER SCHEDULING ALGORITHM Ana I. Pérez-Neira1,2, Po... more Page 1. A LOW COMPLEXITY SPACE-FREQUENCY MULTIUSER SCHEDULING ALGORITHM Ana I. Pérez-Neira1,2, Pol Henarejos1, Velio Tralli3, Miguel A. Lagunas1,2 email: [email protected], [email protected], [email protected], [email protected] (1) Dept. ...
ABSTRACT This article describes the implementation of a prototype visible light communications sy... more ABSTRACT This article describes the implementation of a prototype visible light communications system based on the IEEE 802.15.7 standard using lowcost commercial off-the-shelf analog devices. The aim of this article is to show that this standard provides a framework that could promote the introduction of applications into the market. Thus, these specifications could be further developed, reducing the gap between the industry and research communities. The implemented prototype makes use of software defined radio platforms to interface between the analog devices and the computer where the signal processing is performed. The use of this concept provides the system with enough flexibility and modularity to include new features in the prototype without requiring long development time.
ABSTRACT The aim of this paper is to present an implementation of a functional IEEE 802.15.7 real... more ABSTRACT The aim of this paper is to present an implementation of a functional IEEE 802.15.7 real-time testbed based on the Software Defined Radio (SDR) concept. This implementation is built with low cost commercial off-the-shelf (COTS) analog devices and the use of Universal Software Radio Peripheral version 2 (USRP2) equipment combined with a generic object-oriented framework that takes advantage of several open source software libraries. The prototype is validated in a controlled laboratory environment with an over-the-air measurement campaign.
In this paper we present our approach regarding the implementation of new wireless radio receiver... more In this paper we present our approach regarding the implementation of new wireless radio receivers exploiting filterbank techniques, using a software-development driven approach. The fact that most of the common radio communication systems share a similar structure has been exploited to create a framework which provides a generic layout and tools to construct reconfigurable transmitters and/or receivers. By combining our own generic object-oriented framework built on top of the GNU Radio software framework with the use of the Universal Software Radio Peripheral version 2 (USRP2), we have been able to quickly implement a working proof of concept of an Uplink (UL) Filterbank Multicarrier (FBMC) receiver, both for Single-Input Single-Output (SISO) and Multiple-Input Multiple-Output (MIMO) scenario, within the 7th European framework project called PHYDYAS. As well, a description of the methodology we have applied from software engineering in order to build this demonstrator is herein included, which shows the suitability of using Software Defined Radio (SDR) technologies for fast prototyping of new wireless communication systems.
OFDMA systems are considered as the promising multiple access scheme of next generation multi-cel... more OFDMA systems are considered as the promising multiple access scheme of next generation multi-cellular wireless systems. In order to ensure the optimum usage of radio resources, OFDMA radio resource management algorithms have to maximize the allocated power and rate of the different subchannels to the users taking also into account the generated co-channel interference between neighboring cells, which affects the received Quality of Service. This paper discusses various schemes for power distribution schemes in multiple co-channel cells. These schemes include centralized and distributed solutions, which may involve various degrees of complexity and related overhead and may employ procedures such as linear programming. Finally, the paper introduces a new solution that uses a network flow model to solve the maximization of the multi-cell system sum rate. The application of spatial beamforming at each cell is suggested in order to better cope with interference.
ABSTRACT This paper presents a low-complexity algorithm for multiuser scheduling and resource all... more ABSTRACT This paper presents a low-complexity algorithm for multiuser scheduling and resource allocation in the Multiple Input Single Output (MISO) downlink channel with Orthogonal Frequency Division Multiple Access (OFDMA). The goal of the algorithm is to maximize the sum-rate on the radio channel and to ensure that the rate assignment is suitably balanced among users. The proposed algorithm uses partial Channel State Information (CSI) and therefore has a reduced feedback requirement. It also allows an on-line implementation, based on an ergodic optimization framework with dual optimization and stochastic approximation. Performance and complexity reduction are quantified by considering comparison with other solutions in a realistic single-cell system configuration. It is shown that the algorithm is effective to balance average rate among users even in heterogeneous and non-stationary channel conditions with lower computational complexity and feedback requirements.
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