The Experts below are selected from a list of 74448 Experts worldwide ranked by ideXlab platform
N C Beaulieu - One of the best experts on this subject based on the ideXlab platform.
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a direct sequence design for Narrowband interference mitigation in impulse radio uwb systems
Global Communications Conference, 2011Co-Authors: Hua Shao, N C BeaulieuAbstract:A direct sequence design is proposed for impulse radio ultra-wide bandwidth systems to suppress the mutual interference between ultra-wide bandwidth wireless and coexisting Narrowband services. Notch frequencies are created in the ultra-wide bandwidth signal spectrum at bands where Narrowband services operate. The direct sequence design has low computational complexity and can be easily implemented in practical systems. Numerical results are provided to show that the direct sequence design can significantly suppress the mutual interference between ultra-wide bandwidth and Narrowband services and highly enhance the integrity of both ultra-wide bandwidth and Narrowband systems.
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direct sequence and time hopping sequence designs for Narrowband interference mitigation in impulse radio uwb systems
IEEE Transactions on Communications, 2011Co-Authors: Hua Shao, N C BeaulieuAbstract:Direct sequence and time-hopping sequence designs are proposed for impulse radio ultra-wide bandwidth systems to suppress the mutual interference between ultra-wide bandwidth wireless and coexisting Narrowband services. Notch frequencies are created in the ultra-wide bandwidth signal spectrum at bands where Narrowband services operate. The direct sequence and the time-hopping sequence designs have low computational complexities and can be easily implemented in practical systems. When combined with the cognitive radio technique, these designs can adapt to channel conditions according to the spectral occupancy information provided by cognitive radio. Numerical results are provided to show that these designs can significantly suppress the mutual interference between ultra-wide bandwidth and Narrowband services. Therefore, the integrity of both ultra-wide bandwidth and Narrowband systems can be highly enhanced.
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a time hopping sequence design for Narrowband interference suppression in impulse radio uwb systems
International Conference on Communications, 2011Co-Authors: Hua Shao, N C BeaulieuAbstract:Impulse radio ultra-wide bandwidth wireless is a fast emerging technology where its applications underlay coexisting Narrowband services over a huge bandwidth. Therefore, the coexistence problem between ultra-wide bandwidth and Narrowband systems warrants investigation. A time-hopping sequence design is proposed for impulse radio ultra-wide bandwidth systems to suppress the mutual interference between ultra-wide bandwidth wireless and coexisting Narrowband service. This sequence design has low computation complexities and can be easily implemented in practical systems. Numerical results are provided to show that the time-hopping sequence design can significantly suppress the mutual interference between ultra-wide bandwidth and Narrowband services, hence, the integrity of both ultra-wide bandwidth and Narrowband systems can be greatly enhanced.
Hua Shao - One of the best experts on this subject based on the ideXlab platform.
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a direct sequence design for Narrowband interference mitigation in impulse radio uwb systems
Global Communications Conference, 2011Co-Authors: Hua Shao, N C BeaulieuAbstract:A direct sequence design is proposed for impulse radio ultra-wide bandwidth systems to suppress the mutual interference between ultra-wide bandwidth wireless and coexisting Narrowband services. Notch frequencies are created in the ultra-wide bandwidth signal spectrum at bands where Narrowband services operate. The direct sequence design has low computational complexity and can be easily implemented in practical systems. Numerical results are provided to show that the direct sequence design can significantly suppress the mutual interference between ultra-wide bandwidth and Narrowband services and highly enhance the integrity of both ultra-wide bandwidth and Narrowband systems.
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direct sequence and time hopping sequence designs for Narrowband interference mitigation in impulse radio uwb systems
IEEE Transactions on Communications, 2011Co-Authors: Hua Shao, N C BeaulieuAbstract:Direct sequence and time-hopping sequence designs are proposed for impulse radio ultra-wide bandwidth systems to suppress the mutual interference between ultra-wide bandwidth wireless and coexisting Narrowband services. Notch frequencies are created in the ultra-wide bandwidth signal spectrum at bands where Narrowband services operate. The direct sequence and the time-hopping sequence designs have low computational complexities and can be easily implemented in practical systems. When combined with the cognitive radio technique, these designs can adapt to channel conditions according to the spectral occupancy information provided by cognitive radio. Numerical results are provided to show that these designs can significantly suppress the mutual interference between ultra-wide bandwidth and Narrowband services. Therefore, the integrity of both ultra-wide bandwidth and Narrowband systems can be highly enhanced.
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a time hopping sequence design for Narrowband interference suppression in impulse radio uwb systems
International Conference on Communications, 2011Co-Authors: Hua Shao, N C BeaulieuAbstract:Impulse radio ultra-wide bandwidth wireless is a fast emerging technology where its applications underlay coexisting Narrowband services over a huge bandwidth. Therefore, the coexistence problem between ultra-wide bandwidth and Narrowband systems warrants investigation. A time-hopping sequence design is proposed for impulse radio ultra-wide bandwidth systems to suppress the mutual interference between ultra-wide bandwidth wireless and coexisting Narrowband service. This sequence design has low computation complexities and can be easily implemented in practical systems. Numerical results are provided to show that the time-hopping sequence design can significantly suppress the mutual interference between ultra-wide bandwidth and Narrowband services, hence, the integrity of both ultra-wide bandwidth and Narrowband systems can be greatly enhanced.
Kyung Sup Kwak - One of the best experts on this subject based on the ideXlab platform.
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Using Non-inear Chirp Waveform to Suppress Narrowband Interference in UWB System
2006 International Symposium on Communications and Information Technologies, 2006Co-Authors: Hanbing Shen, Weihua Zhang, Kyung Sup KwakAbstract:In the approved frequency band of ultra-wideband (UWB), some Narrowband communication applications are concernful interference sources. UWB systems are affected by these Narrowband interference sources and the system performance drops down with the interference power increased. This paper offers a method of suppressing this inband Narrowband interference by introducing a kind of non-linear chirp waveform. By using proposed non-linear chirp waveform, the effects of one or more Narrowband interference sources with different frequencies can be suppressed. System performance of the UWB system in the Narrowband interference environment can be improved. Computer simulations are executed in different scenarios and simulation results confirm that the proposed schemes are better than the traditional linear chirp ones
Stephen D. Voran - One of the best experts on this subject based on the ideXlab platform.
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Subjective ratings of instantaneous and gradual transitions from Narrowband to wideband active speech
2010 IEEE International Conference on Acoustics Speech and Signal Processing, 2010Co-Authors: Stephen D. VoranAbstract:In advanced heterogeneous telecommunication networks, network resources can dynamically dictate the type of speech coding that is used. An increase in resources allows for lower coding distortion or it might also be used to provide wideband speech instead of Narrowband speech. Existing studies have demonstrated that wideband speech is preferred to Narrowband speech, but they have also demonstrated that an abrupt transition from Narrowband to wideband is perceived as an impairment, even though it is a transition to a higher quality signal. We describe our recent work that resulted in subjective scores for abrupt and gradual transitions from Narrowband to wideband at the midpoint of a six-second segment of active speech. On average, signals that start Narrowband and end wideband are rated slightly lower than constant Narrowband signals and results are nearly the same for abrupt and gradual (2.5 second) transitions. Scores from 20 listeners show a wide range of individual opinions so we conclude that studies of bandwidth transitions may be quite sensitive to the listener population sample.
Farinaz Edalat - One of the best experts on this subject based on the ideXlab platform.
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SWIFT: A Narrowband-Friendly Cognitive Wideband Network
2020Co-Authors: Charles G Sodini, Dina Katabi, Nate Kushman, Farinaz Edalat, Hariharan RahulAbstract:Wideband technologies in the unlicensed spectrum can satisfy the ever-increasing demands for wireless bandwidth created by emerging rich media applications. The key challenge for such systems, however, is to allow Narrowband technologies that share these bands (say, 802.11 a/b/g/n, Zigbee) to achieve their normal performance, without compromising the throughput or range of the wideband network. This paper presents SWIFT, the first system where high-throughput wideband nodes are shown in a working deployment to coexist with unknown Narrowband devices, while forming a network of their own. Prior work avoids Narrowband devices by operating below the noise level and limiting itself to a single contiguous unused band. While this achieves coexistence, it sacrifices the throughput and operating distance of the wideband device. In contrast, SWIFT creates highthroughput wireless links by weaving together non-contiguous unused frequency bands that change as Narrowband devices enter or leave the environment. This design principle of cognitive aggregation allows SWIFT to achieve coexistence, while operating at normal power, and thereby obtaining higher throughput and greater operating range. We implement SWIFT on a wideband hardware platform, and evaluate it in the presence of 802.11 devices. In comparison to a baseline that coexists with Narrowband devices by operating below their noise level, SWIFT is equally Narrowband-friendly but achieves 3.6−10.5× higher throughput and 6× greater range.
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learning to share Narrowband friendly wideband networks
ACM Special Interest Group on Data Communication, 2008Co-Authors: Hariharan Rahul, Nate Kushman, Dina Katabi, Charles G Sodini, Farinaz EdalatAbstract:Wideband technologies in the unlicensed spectrum can satisfy the ever-increasing demands for wireless bandwidth created by emerging rich media applications. The key challenge for such systems, however, is to allow Narrowband technologies that share these bands (say, 802.11 a/b/g/n, Zigbee) to achieve their normal performance, without compromising the throughput or range of the wideband network. This paper presents SWIFT, the first system where high-throughput wideband nodes are shown in a working deployment to coexist with unknown Narrowband devices, while forming a network of their own. Prior work avoids Narrowband devices by operating below the noise level and limiting itself to a single contiguous unused band. While this achieves coexistence, it sacrifices the throughput and operating distance of the wideband device. In contrast, SWIFT creates high throughput wireless links by weaving together non-contiguous unused frequency bands that change as Narrowband devices enter or leave the environment. This design principle of cognitive aggregation allows SWIFT to achieve coexistence, while operating at normal power, and thereby obtaining higher throughput and greater operating range. We implement SWIFT on a wideband hardware platform, and evaluate it in the presence of 802.11 devices. In comparison to a baseline that coexists with Narrowband devices by operating below their noise level, SWIFT is equally Narrowband-friendly but achieves 3.6-10.5x higher throughput and 6x greater range.
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SIGCOMM - Learning to share: Narrowband-friendly wideband networks
Proceedings of the ACM SIGCOMM 2008 conference on Data communication - SIGCOMM '08, 2008Co-Authors: Hariharan Rahul, Nate Kushman, Dina Katabi, Charles G Sodini, Farinaz EdalatAbstract:Wideband technologies in the unlicensed spectrum can satisfy the ever-increasing demands for wireless bandwidth created by emerging rich media applications. The key challenge for such systems, however, is to allow Narrowband technologies that share these bands (say, 802.11 a/b/g/n, Zigbee) to achieve their normal performance, without compromising the throughput or range of the wideband network. This paper presents SWIFT, the first system where high-throughput wideband nodes are shown in a working deployment to coexist with unknown Narrowband devices, while forming a network of their own. Prior work avoids Narrowband devices by operating below the noise level and limiting itself to a single contiguous unused band. While this achieves coexistence, it sacrifices the throughput and operating distance of the wideband device. In contrast, SWIFT creates high throughput wireless links by weaving together non-contiguous unused frequency bands that change as Narrowband devices enter or leave the environment. This design principle of cognitive aggregation allows SWIFT to achieve coexistence, while operating at normal power, and thereby obtaining higher throughput and greater operating range. We implement SWIFT on a wideband hardware platform, and evaluate it in the presence of 802.11 devices. In comparison to a baseline that coexists with Narrowband devices by operating below their noise level, SWIFT is equally Narrowband-friendly but achieves 3.6-10.5x higher throughput and 6x greater range.
