The Experts below are selected from a list of 183 Experts worldwide ranked by ideXlab platform
Yue Gao - One of the best experts on this subject based on the ideXlab platform.
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distributed compressive sensing augmented wideband spectrum sharing for cognitive iot
IEEE Internet of Things Journal, 2018Co-Authors: Xingjian Zhang, Yue Gao, Zhixun Xie, Zhiqin Xie, Minxiu Zhang, Xiaodong Wang, Guangliang WeiAbstract:The increasing number of Internet of Things (IoT) objects has been a growing challenge of the current spectrum supply. To handle this issue, the IoT devices should have cognitive capabilities to access the unoccupied portion of the wideband spectrum. However, most IoT devices are difficult to perform wideband spectrum sensing using either conventional Nyquist sampling system or sub-Nyquist sampling system since both power-hungry sampling components and intricate sub-Nyquist sampling hardware are unrealistic in the power-constrained IoT paradigm. In this paper, we propose a blind joint sub-Nyquist sensing scheme by utilizing the surround IoT devices to jointly sample the spectrum based on the multicoset sampling theory. Thus, only the off-the-shelf low-rate analog-to-digital converters on the IoT devices are required to form coset samplers and only the minimum number of coset samplers are adopted without the prior knowledge of the number of occupied channels and signal-to-noise ratios. Moreover, to further reduce the number of coset samplers and transfer part of the computational burden from the IoT devices to the core network, we adopt the data from geo-location Database when applicable. The experimental results on both simulated and real-world signals verify the theoretical results and effectiveness of the proposed scheme. At the meanwhile, it is shown that the adaptive number of coset samplers could be adopted without causing the degradation of the detection performance and the number of coset samplers could be further reduced with the assists from Geolocation Database even when the obtained information is partially correct.
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joint sub nyquist spectrum sensing scheme with Geolocation Database over tv white space
IEEE Transactions on Vehicular Technology, 2018Co-Authors: Xingjian Zhang, Yue GaoAbstract:To maximize spectrum access opportunities for white space devices, incorporating real-time spectrum sensing with Geolocation Database is a promising approach to enhance detection resolution with reduced computation complexity. Advanced spectrum sensing techniques are needed to quickly and accurately identify spectrum occupancy over a wide frequency range. However, the stringent requirements from wideband signal acquisition and processing pose a major implementation challenge in compact devices with limited energy storage and computation capabilities. In this paper, a hybrid scheme of sub-Nyquist wideband spectrum sensing with Geolocation Database is proposed to achieve accurate detection of the surrounding spectrum with reduced number of required measurements and computation complexity. Two iterative algorithms are modified to incorporate a priori information from Geolocation Database, therefore enabling spectrum sensing to be performed only on a limited number of potentially vacant channels over TV white space. Theoretical analyses and simulation results show that the proposed joint scheme speeds up the sensing process with enhanced detection performance and smaller required sampling rate, whereas the updated channel information from wideband spectrum sensing reduces the risk of interferences to the dynamic incumbent users.
Xingjian Zhang - One of the best experts on this subject based on the ideXlab platform.
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distributed compressive sensing augmented wideband spectrum sharing for cognitive iot
IEEE Internet of Things Journal, 2018Co-Authors: Xingjian Zhang, Yue Gao, Zhixun Xie, Zhiqin Xie, Minxiu Zhang, Xiaodong Wang, Guangliang WeiAbstract:The increasing number of Internet of Things (IoT) objects has been a growing challenge of the current spectrum supply. To handle this issue, the IoT devices should have cognitive capabilities to access the unoccupied portion of the wideband spectrum. However, most IoT devices are difficult to perform wideband spectrum sensing using either conventional Nyquist sampling system or sub-Nyquist sampling system since both power-hungry sampling components and intricate sub-Nyquist sampling hardware are unrealistic in the power-constrained IoT paradigm. In this paper, we propose a blind joint sub-Nyquist sensing scheme by utilizing the surround IoT devices to jointly sample the spectrum based on the multicoset sampling theory. Thus, only the off-the-shelf low-rate analog-to-digital converters on the IoT devices are required to form coset samplers and only the minimum number of coset samplers are adopted without the prior knowledge of the number of occupied channels and signal-to-noise ratios. Moreover, to further reduce the number of coset samplers and transfer part of the computational burden from the IoT devices to the core network, we adopt the data from geo-location Database when applicable. The experimental results on both simulated and real-world signals verify the theoretical results and effectiveness of the proposed scheme. At the meanwhile, it is shown that the adaptive number of coset samplers could be adopted without causing the degradation of the detection performance and the number of coset samplers could be further reduced with the assists from Geolocation Database even when the obtained information is partially correct.
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joint sub nyquist spectrum sensing scheme with Geolocation Database over tv white space
IEEE Transactions on Vehicular Technology, 2018Co-Authors: Xingjian Zhang, Yue GaoAbstract:To maximize spectrum access opportunities for white space devices, incorporating real-time spectrum sensing with Geolocation Database is a promising approach to enhance detection resolution with reduced computation complexity. Advanced spectrum sensing techniques are needed to quickly and accurately identify spectrum occupancy over a wide frequency range. However, the stringent requirements from wideband signal acquisition and processing pose a major implementation challenge in compact devices with limited energy storage and computation capabilities. In this paper, a hybrid scheme of sub-Nyquist wideband spectrum sensing with Geolocation Database is proposed to achieve accurate detection of the surrounding spectrum with reduced number of required measurements and computation complexity. Two iterative algorithms are modified to incorporate a priori information from Geolocation Database, therefore enabling spectrum sensing to be performed only on a limited number of potentially vacant channels over TV white space. Theoretical analyses and simulation results show that the proposed joint scheme speeds up the sensing process with enhanced detection performance and smaller required sampling rate, whereas the updated channel information from wideband spectrum sensing reduces the risk of interferences to the dynamic incumbent users.
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an efficient joint sub nyquist spectrum sensing scheme with Geolocation Database over tv white space
International Conference on Communications, 2017Co-Authors: Xingjian Zhang, Yue Gao Queen MaryAbstract:To maximize spectrum access opportunities for white space devices, incorporating real-time spectrum sensing with Geolocation Database is a promising approach to enhance detection resolution. Advanced spectrum sensing techniques are needed to quickly and accurately identify spectrum occupancy over a wide frequency range. However, the stringent requirements from the wideband signal acquisition and processing pose a major implementation challenge in compact devices with limited energy storage and computational capabilities. In this paper, an efficient joint scheme of sub-Nyquist wideband spectrum sensing with Geolocation Database is proposed to ensure accurate detection of the surrounding spectrum with reduced number of measurements. Subspace augmented greedy algorithm is modified to incorporate a priori information from Geolocation Database, therefore enabling local spectrum sensing to be performed only on a limited number of potentially vacant channels over TV White Space. Theoretical analysis and experimental results on the simulated and real-time signals show that the proposed joint scheme improves the sensing sensitivity with lower computation complexity, while the updated channel information from local sensing reduces the risk of interferences to the primary users.
Animesh Kumar - One of the best experts on this subject based on the ideXlab platform.
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optimal quantization of tv white space regions for a broadcast based Geolocation Database
European Signal Processing Conference, 2016Co-Authors: Garima Maheshwari, Animesh KumarAbstract:Currently, TV white space Databases communicate the available channels over a reliable Internet connection to the secondary devices. For places where an Internet connection is not available, such as in developing countries, we propose a broadcast based Geolocation Database. This proposed Geolocation Database will broadcast the TV white space (or the primary services protection regions) on a rate-constrained channel. In this work, the feasibility of a broadcast based Geolocation Database transmission will be examined over rate constrained satellite channels. To address this problem, the quantization or digital representation of primary services protection regions is considered. Due to the quantization process, any point in the protection region must not be declared as white space region. Thus, this quantization problem is different than traditional quantizers which minimize the mean-squared error. A quantizer design algorithm is the main result of this work, which minimizes the TV white space area declared as protected region due to quantization. Performance results of our quantization algorithm on US and India UHF-band protection regions will be shown. The update-rate versus bandwidth tradeoff, while using satellite TV channels, for the proposed broadcast based Geolocation Database will also be explored in this work.
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optimal quantization of tv white space regions for a broadcast based Geolocation Database
arXiv: Information Theory, 2015Co-Authors: Garima Maheshwari, Animesh KumarAbstract:In the current paradigm, TV white space Databases communicate the available channels over a reliable Internet connection to the secondary devices. For places where an Internet connection is not available, such as in developing countries, a broadcast based Geolocation Database can be considered. This Geolocation Database will broadcast the TV white space (or the primary services protection regions) on rate-constrained digital channel. In this work, the quantization or digital representation of protection regions is considered for rate-constrained broadcast Geolocation Database. Protection regions should not be declared as white space regions due to the quantization error. In this work, circular and basis based approximations are presented for quantizing the protection regions. In circular approximation, quantization design algorithms are presented to protect the primary from quantization error while minimizing the white space area declared as protected region. An efficient quantizer design algorithm is presented in this case. For basis based approximations, an efficient method to represent the protection regions by an `envelope' is developed. By design this envelope is a sparse approximation, i.e., it has lesser number of non-zero coefficients in the basis when compared to the original protection region. The approximation methods presented in this work are tested using three experimental data-sets.
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openpaws an open source paws and uhf tv white space Database implementation for india
National Conference on Communications, 2015Co-Authors: Soumik Ghosh, Animesh Kumar, Gaurang Naik, Abhay KarandikarAbstract:TV white space (TVWS) Geolocation Database is being used for the protection of the terrestrial TV broadcast receivers, and the coexistence of secondary devices. To the best of our knowledge, though TV White Space calculations are available, an active online Database does not exist for India. In this paper, the development of the first TVWS Database for India is detailed and is released for public access. A standardized protocol to access the TVWS Database on a readily available hardware platform is implemented. A hardware prototype, which is capable of querying the TVWS Database and operating in the TV band without causing harmful interference to the TV receivers in UHF TV bands, is developed. The source code of our implementation has been released under the GNU general public license version 2.0.
Oliver Holland - One of the best experts on this subject based on the ideXlab platform.
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Geolocation based architecture for heterogeneous spectrum usage in 5g
Global Communications Conference, 2015Co-Authors: Oliver Holland, Mischa DohlerAbstract:It is becoming clear that one key characteristic of 5G communication systems will be heterogeneity. Heterogeneity is important to be able to reuse equipment that is available, extract maximum capacity from what is allowed to be used in given spectrum bands and locations due to regulatory limitations, and to match capabilities to the extremely wide range of use cases of 5G. Importantly, this heterogeneity will extend to the use of a range of different spectrum bands and spectrum types. Moreover, 5G must be supported extensively by lower-frequency options; millimeter-wave will be groundbreaking, but for propagation reasons can't be the only solution to serve 5G, e.g., in achieving five-nines reliability. A key to realising lower-frequency spectrum for broadband (including mobile) communications systems is spectrum sharing. This has been emphasised by various reports by bodies such as the President's Council of Advisors on Science and Technology in the US, and the European Commission in the EU. It is also noted that high-profile efforts such as TV White Space (TVWS) and the 3.5 GHz "Innovation Band" in the US imply Geolocation Database-assisted spectrum sharing as the solution to realising this extra capacity. This paper proposes the broad introduction of a Geolocation Database-based system to assist heterogeneous spectrum usage and spectrum sharing in 5G - both to enable 5G systems to use spectrum assigned to other services (e.g., TV spectrum, as in the TVWS example), and to enable 5G systems operating under different operators/owners to share spectrum with each other. This paper also argues for the Geolocation Databases to act as a management capability among secondary/opportunistic networks and devices, to better allocate resources, or combinations (aggregations) thereof, in the light of traffic requirements. The benefits of the approach are shown through reference to performances achieved by the authors within a major regulator-driven trial of TVWS in the UK. Further architectural observations are derived based on those performances. It is important to note that this paper only proposes the high-level nature of such an architecture. Extensive detail is currently impossible to provide given that the basic architectural assumptions for 5G systems are not yet known.
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some initial results and observations from a series of trials within the ofcom tv white spaces pilot
Vehicular Technology Conference, 2015Co-Authors: Oliver Holland, Nishanth Sastry, Shuyu Ping, Pravir Chawdhry, Jeanmarc Chareau, James Bishop, Hong Xing, Suleyman Taskafa, Adnan Aijaz, Michele BavaroAbstract:TV White Spaces (TVWS) technology allows wireless devices to opportunistically use locally-available TV channels enabled by a Geolocation Database. The UK regulator Ofcom has initiated a pilot of TVWS technology in the UK. This paper concerns a large- scale series of trials under that pilot. The purposes are to test aspects of white space technology, including the white space device and Geolocation Database interactions, the validity of the channel availability/powers calculations by the Database and associated interference effects on primary services, and the performances of the white space devices, among others. An additional key purpose is to perform research investigations such as on aggregation of TVWS resources with conventional resources and also aggregation solely within TVWS, secondary coexistence issues and means to mitigate such issues, and primary coexistence issues under challenging deployment geometries, among others. This paper provides an update on the trials, giving an overview of their objectives and characteristics, some aspects that have been covered, and some early results and observations.
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A series of trials in the UK as part of the Ofcom TV white spaces pilot
2014 1st International Workshop on Cognitive Cellular Systems (CCS), 2014Co-Authors: Oliver Holland, Nishanth Sastry, Shuyu Ping, Raymond Knopp, Florian Kaltenberger, Dominique Nussbaum, Juhani Hallio, Mikko Jakobsson, Jani Auranen, Reijo EkmanAbstract:TV White Spaces technology is a means of allowing wireless devices to opportunistically use locally-available TV channels (TV White Spaces), enabled by a Geolocation Database. The Geolocation Database informs the device of which channels can be used at a given location, and in the UK/EU case, which transmission powers (EIRPs) can be used on each channel based on the technical characteristics of the device, given an assumed interference limit and protection margin at the edge of the primary service coverage area(s). The UK regulator, Ofcom, has initiated a large-scale Pilot of TV White Spaces technology and devices. The ICT-ACROPOLIS Network of Excellence, teaming up with the ICT-SOLDER project and others, is running an extensive series of trials under this effort. The purpose of these trials is to test a number of aspects of white space technology, including the white space device and Geolocation Database interactions, the validity of the channel availability/powers calculations by the Database and associated interference effects on primary services., and the performances of the white spaces devices, among others. An additional key purpose is to undertake a number of research investigations such as into aggregation of TV White Space resources with conventional (licensed/unlicensed) resources, secondary coexistence issues and means to mitigate such issues, and primary coexistence issues under challenging deployment geometries, among others. This paper describes our trials, their intentions and characteristics, objectives, and some early observations.
Garima Maheshwari - One of the best experts on this subject based on the ideXlab platform.
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optimal quantization of tv white space regions for a broadcast based Geolocation Database
European Signal Processing Conference, 2016Co-Authors: Garima Maheshwari, Animesh KumarAbstract:Currently, TV white space Databases communicate the available channels over a reliable Internet connection to the secondary devices. For places where an Internet connection is not available, such as in developing countries, we propose a broadcast based Geolocation Database. This proposed Geolocation Database will broadcast the TV white space (or the primary services protection regions) on a rate-constrained channel. In this work, the feasibility of a broadcast based Geolocation Database transmission will be examined over rate constrained satellite channels. To address this problem, the quantization or digital representation of primary services protection regions is considered. Due to the quantization process, any point in the protection region must not be declared as white space region. Thus, this quantization problem is different than traditional quantizers which minimize the mean-squared error. A quantizer design algorithm is the main result of this work, which minimizes the TV white space area declared as protected region due to quantization. Performance results of our quantization algorithm on US and India UHF-band protection regions will be shown. The update-rate versus bandwidth tradeoff, while using satellite TV channels, for the proposed broadcast based Geolocation Database will also be explored in this work.
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optimal quantization of tv white space regions for a broadcast based Geolocation Database
arXiv: Information Theory, 2015Co-Authors: Garima Maheshwari, Animesh KumarAbstract:In the current paradigm, TV white space Databases communicate the available channels over a reliable Internet connection to the secondary devices. For places where an Internet connection is not available, such as in developing countries, a broadcast based Geolocation Database can be considered. This Geolocation Database will broadcast the TV white space (or the primary services protection regions) on rate-constrained digital channel. In this work, the quantization or digital representation of protection regions is considered for rate-constrained broadcast Geolocation Database. Protection regions should not be declared as white space regions due to the quantization error. In this work, circular and basis based approximations are presented for quantizing the protection regions. In circular approximation, quantization design algorithms are presented to protect the primary from quantization error while minimizing the white space area declared as protected region. An efficient quantizer design algorithm is presented in this case. For basis based approximations, an efficient method to represent the protection regions by an `envelope' is developed. By design this envelope is a sparse approximation, i.e., it has lesser number of non-zero coefficients in the basis when compared to the original protection region. The approximation methods presented in this work are tested using three experimental data-sets.