The Experts below are selected from a list of 65559 Experts worldwide ranked by ideXlab platform
Lajos Hanzo - One of the best experts on this subject based on the ideXlab platform.
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Dual-Layered MIMO Transmission for Increased Bandwidth Efficiency
IEEE Transactions on Vehicular Technology, 2016Co-Authors: Christos Masouros, Lajos HanzoAbstract:A dual-layered downlink transmission scheme is proposed for intrinsically amalgamating multiple-input–multiple-output (MIMO) spatial multiplexing (SMX) with spatial modulation (SM). The proposed scheme employs a classic SMX transmission that is known to offer superior Bandwidth Efficiency (BE) compared with SM. We exploit receive-antenna-based SM (RSM) on top of this transmission as an enhancement of the BE. The RSM here is applied to the combined spatial and power-level domain not by activating and deactivating the RAs but rather by choosing between two power levels $\{P_1,P_2\}$ for the received symbols in these antennas. In other words, the combination of symbols received at a power level $P_1$ carries information in the spatial domain in the same manner as the combination of nonzero elements in the receive symbol vector carries information in the RSM transmission. This allows for the coexistence of RSM with SMX, and the results show increased BE for the proposed scheme compared with both SMX and SM. To characterize the proposed scheme, we carry out a mathematical analysis of its performance, and we use this to optimize the ratio between $P_1$ and $P_2$ for attaining the minimum error rates. Our analytical and simulation results demonstrate significant BE gains for the proposed scheme compared with conventional SMX and SM.
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power versus Bandwidth Efficiency in wireless communications the economic perspective
Vehicular Technology Conference, 2009Co-Authors: J Akhtman, Lajos HanzoAbstract:We carry out a comprehensive analysis of a range of wireless network Efficiency considerations. Firstly, we explore the properties and the implications of the power- versus Bandwidth-Efficiency criteria. Secondly, we perform a detailed top-down analysis of a typical commercial wireless network, which emphasizes the inherent differences between the aforementioned two Efficiency metrics, while demonstrating that the appropriate choice of the network optimization criterion can have a profound effect on the overall network performance. Finally, we address the issue of resource management and its impact on the definition of the overall system Efficiency.
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VTC Fall - Power Versus Bandwidth-Efficiency in Wireless Communications: The Economic Perspective
2009 IEEE 70th Vehicular Technology Conference Fall, 2009Co-Authors: J Akhtman, Lajos HanzoAbstract:We carry out a comprehensive analysis of a range of wireless network Efficiency considerations. Firstly, we explore the properties and the implications of the power- versus Bandwidth-Efficiency criteria. Secondly, we perform a detailed top-down analysis of a typical commercial wireless network, which emphasizes the inherent differences between the aforementioned two Efficiency metrics, while demonstrating that the appropriate choice of the network optimization criterion can have a profound effect on the overall network performance. Finally, we address the issue of resource management and its impact on the definition of the overall system Efficiency.
J Akhtman - One of the best experts on this subject based on the ideXlab platform.
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power versus Bandwidth Efficiency in wireless communications the economic perspective
Vehicular Technology Conference, 2009Co-Authors: J Akhtman, Lajos HanzoAbstract:We carry out a comprehensive analysis of a range of wireless network Efficiency considerations. Firstly, we explore the properties and the implications of the power- versus Bandwidth-Efficiency criteria. Secondly, we perform a detailed top-down analysis of a typical commercial wireless network, which emphasizes the inherent differences between the aforementioned two Efficiency metrics, while demonstrating that the appropriate choice of the network optimization criterion can have a profound effect on the overall network performance. Finally, we address the issue of resource management and its impact on the definition of the overall system Efficiency.
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VTC Fall - Power Versus Bandwidth-Efficiency in Wireless Communications: The Economic Perspective
2009 IEEE 70th Vehicular Technology Conference Fall, 2009Co-Authors: J Akhtman, Lajos HanzoAbstract:We carry out a comprehensive analysis of a range of wireless network Efficiency considerations. Firstly, we explore the properties and the implications of the power- versus Bandwidth-Efficiency criteria. Secondly, we perform a detailed top-down analysis of a typical commercial wireless network, which emphasizes the inherent differences between the aforementioned two Efficiency metrics, while demonstrating that the appropriate choice of the network optimization criterion can have a profound effect on the overall network performance. Finally, we address the issue of resource management and its impact on the definition of the overall system Efficiency.
Massoud Pedram - One of the best experts on this subject based on the ideXlab platform.
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WOWMOM - Heterogeneous modulation for trading-off energy balancing with Bandwidth Efficiency in hierarchical sensor networks
2008 International Symposium on a World of Wireless Mobile and Multimedia Networks, 2008Co-Authors: M. Soltan, Inkwon Hwang, Massoud PedramAbstract:With power Efficiency and lifetime awareness becoming critical design concerns in wireless sensor networks (WSN), it has become essential to exploit the physical layer characteristics at the system deployment stage. This paper focuses on how certain physical layer attributes can affect both the lifetime and the end-to-end delay in a hierarchical WSN. We present a heterogeneous modulation scheme and report its impact on the spatial distribution of energy dissipation and the resulting network lifetime. Moreover, we study how this heterogeneous modulation scheme affects the end-to-end delay due to inherent trade-offs in power Efficiency and Bandwidth Efficiency of the different modulation schemes.
M. S. Ünlü - One of the best experts on this subject based on the ideXlab platform.
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high Bandwidth Efficiency solar blind algan schottky photodiodes with low dark current
Solid-state Electronics, 2005Co-Authors: Turgut Tut, Necmi Biyikli, I. Kimukin, Orhan Aytür, M. S. Ünlü, Tolga Kartaloglu, Ekmel OzbayAbstract:Abstract Al 0.38 Ga 0.62 N/GaN heterojunction solar-blind Schottky photodetectors with low dark current, high responsivity, and fast pulse response were demonstrated. A five-step microwave compatible fabrication process was utilized to fabricate the devices. The solar-blind detectors displayed extremely low dark current values: 30 μm diameter devices exhibited leakage current below 3 fA under reverse bias up to 12 V. True solar-blind operation was ensured with a sharp cut-off around 266 nm. Peak responsivity of 147 mA/W was measured at 256 nm under 20 V reverse bias. A visible rejection more than 4 orders of magnitude was achieved. The thermally-limited detectivity of the devices was calculated as 1.8 × 10 13 cm Hz 1/2 W −1 . Temporal pulse response measurements of the solar-blind detectors resulted in fast pulses with high 3-dB Bandwidths. The best devices had 53 ps pulse-width and 4.1 GHz Bandwidth. A Bandwidth-Efficiency product of 2.9 GHz was achieved with the AlGaN Schottky photodiodes.
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45-GHz Bandwidth-Efficiency resonant-cavity-enhanced ITO-Schottky photodiodes
IEEE Photonics Technology Letters, 2001Co-Authors: Necmi Biyikli, I. Kimukin, Orhan Aytür, Ekmel Ozbay, Mutlu Gokkavas, M. S. ÜnlüAbstract:High-speed Schottky photodiodes suffer from low Efficiency mainly due to the thin absorption layers and the semitransparent Schottky-contact metals. We have designed, fabricated and characterized high-speed and high-Efficiency AlGaAs-GaAs-based Schottky photodiodes using transparent indium-tin-oxide Schottky contact material and resonant cavity enhanced detector structure. The measured devices displayed resonance peaks around 820 nm with 75% maximum peak Efficiency and an experimental setup limited temporal response of 11 ps pulsewidth. The resulting 45-GHz Bandwidth-Efficiency product obtained from these devices corresponds to the best performance reported to date for vertically illuminated Schottky photodiodes.
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high Bandwidth Efficiency resonant cavity enhanced schottky photodiodes for 800 850 nm wavelength operation
Applied Physics Letters, 1998Co-Authors: M. S. Ünlü, Richard P Mirin, Ekmel Ozbay, Mutlu Gokkavas, B M Onat, Kevin J Knopp, Kristine A Bertness, David H ChristensenAbstract:High-speed resonant cavity enhanced Schottky photodiodes operating in 800–850 nm wavelength region are demonstrated. The devices are fabricated in the AlGaAs/GaAs material system. The Schottky contact is a semitransparent Au film which also serves as the top reflector of the Fabry–Perot cavity. The detectors exhibit a peak quantum Efficiency of η=0.5 at λ=827 nm wavelength and a 3 dB Bandwidth of more than 50 GHz resulting in a Bandwidth-Efficiency product of more than 25 GHz.
Richard P Mirin - One of the best experts on this subject based on the ideXlab platform.
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high Bandwidth Efficiency resonant cavity enhanced schottky photodiodes for 800 850 nm wavelength operation
Applied Physics Letters, 1998Co-Authors: M. S. Ünlü, Richard P Mirin, Ekmel Ozbay, Mutlu Gokkavas, B M Onat, Kevin J Knopp, Kristine A Bertness, David H ChristensenAbstract:High-speed resonant cavity enhanced Schottky photodiodes operating in 800–850 nm wavelength region are demonstrated. The devices are fabricated in the AlGaAs/GaAs material system. The Schottky contact is a semitransparent Au film which also serves as the top reflector of the Fabry–Perot cavity. The detectors exhibit a peak quantum Efficiency of η=0.5 at λ=827 nm wavelength and a 3 dB Bandwidth of more than 50 GHz resulting in a Bandwidth-Efficiency product of more than 25 GHz.
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travelling wave photodetectors with 172 ghz Bandwidth and 76 ghz Bandwidth Efficiency product
IEEE Photonics Technology Letters, 1995Co-Authors: K Giboney, Mark J. W. Rodwell, Radhakrishnan L Nagarajan, T E Reynolds, S T Allen, Richard P Mirin, John E BowersAbstract:Results of the first fabrication and measurement of travelling-wave photodetectors are reported. The devices have Bandwidths as high as 172 GHz, the highest reported for a p-i-n photodetector, and Bandwidth-Efficiency products as large as 76 GHz, the largest reported for any photodetector without gain. Comparisons with vertically illuminated and waveguide photodetectors fabricated on the same wafer establish the superior performance of travelling-wave photodetectors. Microwave loss on the travelling-wave photodetector structure is identified as a Bandwidth limitation. >
