Pub Date : 2011-05-08DOI: 10.1109/CTS.2011.5898924
Hatem Yousry, A. Elezabi, F. Newagy, S. El-Ramly
Spectrum sensing has been identified as a key enabling functionality to ensure that cognitive radios would not interfere with the primary users, by reliably detecting primary user signal. In this paper, the primary user signal is wireless microphone (WM) signal. The power of the WM signal is highly concentrated in the frequency domain. Due to this property, we focus on spectrum sensing in the frequency domain. The most common and simplest method is energy detection (ED), which suffers from large degradation in performance under low signal-to-noise ratio (SNR) environment. To overcome this problem, an Improved Periodogram-Based (IPB) technique is proposed. Averaging the power spectral density (PSD) of segmented overlapped samples with different window shapes is proposed in IPB. We also examine the optimum segmentation for a given sensing time and obtain the optimum number of segments in the region satisfying the probability of false alarm constraint.
{"title":"Improved Periodogram-Based spectrum sensing technique for FM wireless microphone signals","authors":"Hatem Yousry, A. Elezabi, F. Newagy, S. El-Ramly","doi":"10.1109/CTS.2011.5898924","DOIUrl":"https://doi.org/10.1109/CTS.2011.5898924","url":null,"abstract":"Spectrum sensing has been identified as a key enabling functionality to ensure that cognitive radios would not interfere with the primary users, by reliably detecting primary user signal. In this paper, the primary user signal is wireless microphone (WM) signal. The power of the WM signal is highly concentrated in the frequency domain. Due to this property, we focus on spectrum sensing in the frequency domain. The most common and simplest method is energy detection (ED), which suffers from large degradation in performance under low signal-to-noise ratio (SNR) environment. To overcome this problem, an Improved Periodogram-Based (IPB) technique is proposed. Averaging the power spectral density (PSD) of segmented overlapped samples with different window shapes is proposed in IPB. We also examine the optimum segmentation for a given sensing time and obtain the optimum number of segments in the region satisfying the probability of false alarm constraint.","PeriodicalId":142306,"journal":{"name":"2011 18th International Conference on Telecommunications","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126786938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-08DOI: 10.1109/CTS.2011.5898941
H. Khodakarami, F. Lahouti
Wireless cooperative communication through link adaptation with untrusted relay assignment is considered. Using sharp channel codes in different transmission modes, reliability for destination and security in the presence of untrusted relays are provided through rate and power allocation. Scenarios with single available relay and opportunistic relaying in the presence of multiple relays are investigated. These scenarios are analyzed separately in terms of performance over Rayleigh fading channel for constant power and adaptive power transmission. In constant power case, closed form expressions for average spectral efficiency is derived through an effective approximation. Retaining the sum transmission power of source and relay unchanged, the performance of system is enhanced through power allocation. Numerical results reflect the effectiveness of the approximations for analytic performance evaluation when comparing to the simulation results.
{"title":"Link adaptation for fixed relaying with untrusted relays: Transmission strategy design and performance analysis","authors":"H. Khodakarami, F. Lahouti","doi":"10.1109/CTS.2011.5898941","DOIUrl":"https://doi.org/10.1109/CTS.2011.5898941","url":null,"abstract":"Wireless cooperative communication through link adaptation with untrusted relay assignment is considered. Using sharp channel codes in different transmission modes, reliability for destination and security in the presence of untrusted relays are provided through rate and power allocation. Scenarios with single available relay and opportunistic relaying in the presence of multiple relays are investigated. These scenarios are analyzed separately in terms of performance over Rayleigh fading channel for constant power and adaptive power transmission. In constant power case, closed form expressions for average spectral efficiency is derived through an effective approximation. Retaining the sum transmission power of source and relay unchanged, the performance of system is enhanced through power allocation. Numerical results reflect the effectiveness of the approximations for analytic performance evaluation when comparing to the simulation results.","PeriodicalId":142306,"journal":{"name":"2011 18th International Conference on Telecommunications","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129166679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-08DOI: 10.1109/CTS.2011.5898967
Zhao Li, Qin Liu, Linjing Zhao
This paper investigates multi-antenna cognitive radio system, designs signal processing algorithms for cognitive uplink transmission, and proposes an opportunistic spectrum access scheme based on space division multiplexing (SDM-OSA). The proposed algorithms take equipment size and complexity constraints for mobile terminal into account and place main workload at cognitive base station, thus facilitate the design of cognitive terminal. With proper antenna configuration, cognitive transmission could be carried out using SDM even though there is no idle spectrum available. Compared with traditional OSA, throughput of cognitive system with proposed method is notably enhanced. Most important, the design guarantees that cognitive system does not interfere with the primary.
{"title":"Multi-antenna cognitive uplink design for spectrum reuse","authors":"Zhao Li, Qin Liu, Linjing Zhao","doi":"10.1109/CTS.2011.5898967","DOIUrl":"https://doi.org/10.1109/CTS.2011.5898967","url":null,"abstract":"This paper investigates multi-antenna cognitive radio system, designs signal processing algorithms for cognitive uplink transmission, and proposes an opportunistic spectrum access scheme based on space division multiplexing (SDM-OSA). The proposed algorithms take equipment size and complexity constraints for mobile terminal into account and place main workload at cognitive base station, thus facilitate the design of cognitive terminal. With proper antenna configuration, cognitive transmission could be carried out using SDM even though there is no idle spectrum available. Compared with traditional OSA, throughput of cognitive system with proposed method is notably enhanced. Most important, the design guarantees that cognitive system does not interfere with the primary.","PeriodicalId":142306,"journal":{"name":"2011 18th International Conference on Telecommunications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128832111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-08DOI: 10.1109/CTS.2011.5898972
C. Campolo, A. Molinaro
A wide variety of applications for Intelligent Transportation Systems (ITSs) require vehicles on the road to be provided with connectivity to the Internet. Due to the high costs for deploying and maintaining an ubiquitous roadside infrastructure, only a few Road-side Units (RSUs) are expected to be initially installed to offer wireless connectivity to vehicles in a VANET (Vehicular Ad hoc Network). Discontinuous radio coverage and high vehicle mobility will cause vehicle-to-roadside (V2R) connectivity to be intermittent and short-lived. In this paper, a proposal aiming to reduce the connectivity gaps between vehicles and the RSU and to improve the radio channel utilization is evaluated when considering the upcoming 802.11p/WAVE standard for vehicular environments. Periodic beaconing from any vehicle and position-aware data rate adaptation are exploited to enhance RSU discovery capability and V2R connectivity.
{"title":"Improving V2R connectivity to provide ITS applications in IEEE 802.11p/WAVE VANETs","authors":"C. Campolo, A. Molinaro","doi":"10.1109/CTS.2011.5898972","DOIUrl":"https://doi.org/10.1109/CTS.2011.5898972","url":null,"abstract":"A wide variety of applications for Intelligent Transportation Systems (ITSs) require vehicles on the road to be provided with connectivity to the Internet. Due to the high costs for deploying and maintaining an ubiquitous roadside infrastructure, only a few Road-side Units (RSUs) are expected to be initially installed to offer wireless connectivity to vehicles in a VANET (Vehicular Ad hoc Network). Discontinuous radio coverage and high vehicle mobility will cause vehicle-to-roadside (V2R) connectivity to be intermittent and short-lived. In this paper, a proposal aiming to reduce the connectivity gaps between vehicles and the RSU and to improve the radio channel utilization is evaluated when considering the upcoming 802.11p/WAVE standard for vehicular environments. Periodic beaconing from any vehicle and position-aware data rate adaptation are exploited to enhance RSU discovery capability and V2R connectivity.","PeriodicalId":142306,"journal":{"name":"2011 18th International Conference on Telecommunications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127565014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-08DOI: 10.1109/CTS.2011.5898928
Jiang Zhang, Yi An, M. Berger, C. Peucheret, A. Clausen
We propose a generic optical network design for future avionic systems in order to reduce the weight and power consumption of current networks on board. A three-layered network structure over a ring optical network topology is suggested, as it can provide full reconfiguration flexibility and support a wide range of avionic applications. Segregation can be made on different hierarchies according to system criticality and security requirements. The structure of each layer is discussed in detail. Two network configurations are presented, focusing on how to support different network services by such a network. Finally, three redundancy scenarios are discussed and compared.
{"title":"Developing a generic optical avionic network","authors":"Jiang Zhang, Yi An, M. Berger, C. Peucheret, A. Clausen","doi":"10.1109/CTS.2011.5898928","DOIUrl":"https://doi.org/10.1109/CTS.2011.5898928","url":null,"abstract":"We propose a generic optical network design for future avionic systems in order to reduce the weight and power consumption of current networks on board. A three-layered network structure over a ring optical network topology is suggested, as it can provide full reconfiguration flexibility and support a wide range of avionic applications. Segregation can be made on different hierarchies according to system criticality and security requirements. The structure of each layer is discussed in detail. Two network configurations are presented, focusing on how to support different network services by such a network. Finally, three redundancy scenarios are discussed and compared.","PeriodicalId":142306,"journal":{"name":"2011 18th International Conference on Telecommunications","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129950513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-08DOI: 10.1109/CTS.2011.5898913
L. Hörmann, Philipp M. Glatz, C. Steger, R. Weiss
Energy harvesting systems (EHSs) are the key to perpetual operation of electronic devices in application areas with bad infrastructure or mobility. Wireless sensor networks (WSNs) are often used in such areas. Normal WSN nodes are powered by batteries. Therefore, the lifetime is limited and the batteries have to be replaced manually after a certain period of time. This problem can be solved by EHSs. They exploit energy sources of the environment and store the harvested energy in energy buffers. The EHS supplies the electronic device and ensures a continuous operation. WSNs can benefit from these developments, because the lifetime can be enhanced dramatically. However, the EHS have to be adapted to the requirements of the application area and of the supplied device. This enhances the overall efficiency of EHS. To be able to do that, the fundamental mode of operation of an EHS has to be well-understood. We introduce a novel tier model for EHSs. It structures the EHS into tiers with special functions. This enhances the design process of an EHS, because tiers can be adapted to each other and the overall efficiency of can be increased. The tier model is applied to RiverMote, a WSN node for in-river water level monitoring. Each node is supplied by solar cells and the energy is stored in double layer capacitors (DLCs). The hardware of the EHS of RiverMote is divided into the tiers of the model. These tiers are adapted to each other carefully. Although no maximum power point tracker has been implemented, it has been shown that the available power of the solar cell is greater than 80 % of the maximum power point if the energy level of the DLCs is between 42 % and 100 %. This result was only possible by a careful design and an adaption of the tiers.
{"title":"Designing of efficient energy harvesting systems for autonomous WSNs using a tier model","authors":"L. Hörmann, Philipp M. Glatz, C. Steger, R. Weiss","doi":"10.1109/CTS.2011.5898913","DOIUrl":"https://doi.org/10.1109/CTS.2011.5898913","url":null,"abstract":"Energy harvesting systems (EHSs) are the key to perpetual operation of electronic devices in application areas with bad infrastructure or mobility. Wireless sensor networks (WSNs) are often used in such areas. Normal WSN nodes are powered by batteries. Therefore, the lifetime is limited and the batteries have to be replaced manually after a certain period of time. This problem can be solved by EHSs. They exploit energy sources of the environment and store the harvested energy in energy buffers. The EHS supplies the electronic device and ensures a continuous operation. WSNs can benefit from these developments, because the lifetime can be enhanced dramatically. However, the EHS have to be adapted to the requirements of the application area and of the supplied device. This enhances the overall efficiency of EHS. To be able to do that, the fundamental mode of operation of an EHS has to be well-understood. We introduce a novel tier model for EHSs. It structures the EHS into tiers with special functions. This enhances the design process of an EHS, because tiers can be adapted to each other and the overall efficiency of can be increased. The tier model is applied to RiverMote, a WSN node for in-river water level monitoring. Each node is supplied by solar cells and the energy is stored in double layer capacitors (DLCs). The hardware of the EHS of RiverMote is divided into the tiers of the model. These tiers are adapted to each other carefully. Although no maximum power point tracker has been implemented, it has been shown that the available power of the solar cell is greater than 80 % of the maximum power point if the energy level of the DLCs is between 42 % and 100 %. This result was only possible by a careful design and an adaption of the tiers.","PeriodicalId":142306,"journal":{"name":"2011 18th International Conference on Telecommunications","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121269982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-08DOI: 10.1109/CTS.2011.5898931
Yonghua Li, Tiejun Lv, J. Xia, Feichi Long
In this paper, a novel signal combining and decision scheme is proposed based on Dempster-Shafer (D-S) evidence theory in multiple antenna system. The focal-element-set (FES) is used to describe the uncertainty for the decision statistics, and the corresponding basic-probability-assignment (BPA) of FES is the likelihood measure, which act as the soft-decisions for the receiver signals. The process is called intelligent deductions and the uncertainty can be counteracted during combining the soft information sources from all received spatial diversity signals, leading to the performance improvement. Simulation results verify that the proposed combining and decision method outperforms conventional combining and decision schemes counterparts with only moderate complexity increases.
{"title":"Intelligent signal combining and decision with D-S theory in multiple antennas wireless communication system","authors":"Yonghua Li, Tiejun Lv, J. Xia, Feichi Long","doi":"10.1109/CTS.2011.5898931","DOIUrl":"https://doi.org/10.1109/CTS.2011.5898931","url":null,"abstract":"In this paper, a novel signal combining and decision scheme is proposed based on Dempster-Shafer (D-S) evidence theory in multiple antenna system. The focal-element-set (FES) is used to describe the uncertainty for the decision statistics, and the corresponding basic-probability-assignment (BPA) of FES is the likelihood measure, which act as the soft-decisions for the receiver signals. The process is called intelligent deductions and the uncertainty can be counteracted during combining the soft information sources from all received spatial diversity signals, leading to the performance improvement. Simulation results verify that the proposed combining and decision method outperforms conventional combining and decision schemes counterparts with only moderate complexity increases.","PeriodicalId":142306,"journal":{"name":"2011 18th International Conference on Telecommunications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121401118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-08DOI: 10.1109/CTS.2011.5898990
Shahin Vakilinia, B. Khalaj, M. H. L. Froushani
In this paper, we propose a distributed rate and power allocation algorithm for real time traffic by using second order statistics of the channel. Our method minimizes the average delay of transmission over the fading channel. We assume that each sub carrier relies on its own buffer, and a constant arrival rate from higher layer application arrives at input buffers of each sub-carrier. This constant rate is optimally distributed through individual sub-rates transmitted over each sub-channel. Optimum power coefficients are also derived to minimize the average delay of transmission. In addition, collision and buffer overflows are taken into account while achieving acceptable throughputs.
{"title":"QoS-aware water-filling for real-time transmission in OFDMA systems","authors":"Shahin Vakilinia, B. Khalaj, M. H. L. Froushani","doi":"10.1109/CTS.2011.5898990","DOIUrl":"https://doi.org/10.1109/CTS.2011.5898990","url":null,"abstract":"In this paper, we propose a distributed rate and power allocation algorithm for real time traffic by using second order statistics of the channel. Our method minimizes the average delay of transmission over the fading channel. We assume that each sub carrier relies on its own buffer, and a constant arrival rate from higher layer application arrives at input buffers of each sub-carrier. This constant rate is optimally distributed through individual sub-rates transmitted over each sub-channel. Optimum power coefficients are also derived to minimize the average delay of transmission. In addition, collision and buffer overflows are taken into account while achieving acceptable throughputs.","PeriodicalId":142306,"journal":{"name":"2011 18th International Conference on Telecommunications","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127024681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-08DOI: 10.1109/CTS.2011.5898930
N. Bonello, S. Aïssa
The global concern on environmental issues is placing its mark on all sectors of the society, including of course, the wireless telecommunications industry. In this paper, we develop a microeconomic-based ‘green’ radio framework in which a network operator shifts some of its responsibilities towards the intended destination to one of these inactive end-users with the specific intention of reducing the transmitted power of its source nodes and the incurred costs. Our results disclose up to 70% energy savings and up to 65% cost savings over the direct transmission benchmarker, when selecting from approximately 50 eligible relays in the scenario portrayed by the UMTS Rel. 99 standard.
{"title":"A microeconomic-based framework for ‘green’ cooperative communications","authors":"N. Bonello, S. Aïssa","doi":"10.1109/CTS.2011.5898930","DOIUrl":"https://doi.org/10.1109/CTS.2011.5898930","url":null,"abstract":"The global concern on environmental issues is placing its mark on all sectors of the society, including of course, the wireless telecommunications industry. In this paper, we develop a microeconomic-based ‘green’ radio framework in which a network operator shifts some of its responsibilities towards the intended destination to one of these inactive end-users with the specific intention of reducing the transmitted power of its source nodes and the incurred costs. Our results disclose up to 70% energy savings and up to 65% cost savings over the direct transmission benchmarker, when selecting from approximately 50 eligible relays in the scenario portrayed by the UMTS Rel. 99 standard.","PeriodicalId":142306,"journal":{"name":"2011 18th International Conference on Telecommunications","volume":"138 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128471595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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