The Experts below are selected from a list of 359631 Experts worldwide ranked by ideXlab platform
Ana García Armada - One of the best experts on this subject based on the ideXlab platform.
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EUSIPCO - Performance of single-user and multi-user Constant-Energy bit loading in Hiperlan channels
2002Co-Authors: Ana García Armada, John M. CioffiAbstract:Several WLAN standards, such as Hiperlan-2, have chosen OFDM as a transmission technique due to its multipath performance. However, in these standards spectrum is not optimized. This paper analyzes the performance of single-user and multi-user Constant-Energy bit loading in Hiperlan channels. We show that bit rates may be increased up to 12 times in the single-user case and a gain of more than 100% may be achieved relative to Hiperlan-2 in multi-user scenarios.
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multi user Constant Energy bit loading for m psk modulated orthogonal frequency division multiplexing
Wireless Communications and Networking Conference, 2002Co-Authors: Ana García Armada, J M CioffiAbstract:Bit loading algorithms use M-ary quadrature amplitude modulation (M-QAM) of the OFDM sub-carriers, where the number of bits modulating each of them is obtained so that either Energy is minimized, rate or margin are maximized. Many of them use the SNR gap approximation for M-QAM signaling, making the algorithm simpler to implement. In some circumstances it may be interesting to use M-ary phase shift keying (M-PSK) instead of M-QAM, e.g. when Golay complementary sequences are used to reduce the PAR (peak-to-average ratio) in OFDM. An approximation is derived for M-PSK similar to the SNR gap of M-QAM, a Constant-Energy bit loading algorithm is described and its performance is compared to a previously reported algorithm using M-QAM.
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Performance of single-user and multi-user Constant-Energy bit loading in Hiperlan channels
2002 11th European Signal Processing Conference, 2002Co-Authors: Ana García Armada, John M. CioffiAbstract:Several WLAN standards, such as Hiperlan-2, have chosen OFDM as a transmission technique due to its multipath performance. However, in these standards spectrum is not optimized. This paper analyzes the performance of single-user and multi-user Constant-Energy bit loading in Hiperlan channels. We show that bit rates may be increased up to 12 times in the single-user case and a gain of more than 100% may be achieved relative to Hiperlan-2 in multi-user scenarios.
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WCNC - Multi-user Constant-Energy bit loading for M-PSK-modulated orthogonal frequency division multiplexing
2002 IEEE Wireless Communications and Networking Conference Record. WCNC 2002 (Cat. No.02TH8609), 1Co-Authors: Ana García Armada, John M. CioffiAbstract:Bit loading algorithms use M-ary quadrature amplitude modulation (M-QAM) of the OFDM sub-carriers, where the number of bits modulating each of them is obtained so that either Energy is minimized, rate or margin are maximized. Many of them use the SNR gap approximation for M-QAM signaling, making the algorithm simpler to implement. In some circumstances it may be interesting to use M-ary phase shift keying (M-PSK) instead of M-QAM, e.g. when Golay complementary sequences are used to reduce the PAR (peak-to-average ratio) in OFDM. An approximation is derived for M-PSK similar to the SNR gap of M-QAM, a Constant-Energy bit loading algorithm is described and its performance is compared to a previously reported algorithm using M-QAM.
John M. Cioffi - One of the best experts on this subject based on the ideXlab platform.
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EUSIPCO - Performance of single-user and multi-user Constant-Energy bit loading in Hiperlan channels
2002Co-Authors: Ana García Armada, John M. CioffiAbstract:Several WLAN standards, such as Hiperlan-2, have chosen OFDM as a transmission technique due to its multipath performance. However, in these standards spectrum is not optimized. This paper analyzes the performance of single-user and multi-user Constant-Energy bit loading in Hiperlan channels. We show that bit rates may be increased up to 12 times in the single-user case and a gain of more than 100% may be achieved relative to Hiperlan-2 in multi-user scenarios.
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Performance of single-user and multi-user Constant-Energy bit loading in Hiperlan channels
2002 11th European Signal Processing Conference, 2002Co-Authors: Ana García Armada, John M. CioffiAbstract:Several WLAN standards, such as Hiperlan-2, have chosen OFDM as a transmission technique due to its multipath performance. However, in these standards spectrum is not optimized. This paper analyzes the performance of single-user and multi-user Constant-Energy bit loading in Hiperlan channels. We show that bit rates may be increased up to 12 times in the single-user case and a gain of more than 100% may be achieved relative to Hiperlan-2 in multi-user scenarios.
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WCNC - Multi-user Constant-Energy bit loading for M-PSK-modulated orthogonal frequency division multiplexing
2002 IEEE Wireless Communications and Networking Conference Record. WCNC 2002 (Cat. No.02TH8609), 1Co-Authors: Ana García Armada, John M. CioffiAbstract:Bit loading algorithms use M-ary quadrature amplitude modulation (M-QAM) of the OFDM sub-carriers, where the number of bits modulating each of them is obtained so that either Energy is minimized, rate or margin are maximized. Many of them use the SNR gap approximation for M-QAM signaling, making the algorithm simpler to implement. In some circumstances it may be interesting to use M-ary phase shift keying (M-PSK) instead of M-QAM, e.g. when Golay complementary sequences are used to reduce the PAR (peak-to-average ratio) in OFDM. An approximation is derived for M-PSK similar to the SNR gap of M-QAM, a Constant-Energy bit loading algorithm is described and its performance is compared to a previously reported algorithm using M-QAM.
Eli Rotenberg - One of the best experts on this subject based on the ideXlab platform.
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characterization of graphene through anisotropy of Constant Energy maps in angle resolved photoemission
Physical Review B, 2008Co-Authors: Marcin Muchakruczynski, O Tsyplyatyev, A Grishin, Edward Mccann, Vladimir I Falko, Aaron Bostwick, Eli RotenbergAbstract:We theoretically show how Constant-Energy maps of the angle-resolved photoemission intensity can be used to test wave function symmetry in graphene. For monolayer graphene, we demonstrate that the observed anisotropy of angle-resolved photoelectron spectroscopy spectra is a manifestation of what has been recently branded as an electronic chirality. For bilayer graphene, we show that the anisotropy of the Constant-Energy maps may be used to extract information about the magnitude and sign of interlayer coupling parameters and about symmetry breaking inflicted on a bilayer by the underlying substrate.
O Tsyplyatyev - One of the best experts on this subject based on the ideXlab platform.
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characterization of graphene through anisotropy of Constant Energy maps in angle resolved photoemission
Physical Review B, 2008Co-Authors: Marcin Muchakruczynski, O Tsyplyatyev, A Grishin, Edward Mccann, Vladimir I Falko, Aaron Bostwick, Eli RotenbergAbstract:We theoretically show how Constant-Energy maps of the angle-resolved photoemission intensity can be used to test wave function symmetry in graphene. For monolayer graphene, we demonstrate that the observed anisotropy of angle-resolved photoelectron spectroscopy spectra is a manifestation of what has been recently branded as an electronic chirality. For bilayer graphene, we show that the anisotropy of the Constant-Energy maps may be used to extract information about the magnitude and sign of interlayer coupling parameters and about symmetry breaking inflicted on a bilayer by the underlying substrate.
Vladimir I Falko - One of the best experts on this subject based on the ideXlab platform.
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characterization of graphene through anisotropy of Constant Energy maps in angle resolved photoemission
Physical Review B, 2008Co-Authors: Marcin Muchakruczynski, O Tsyplyatyev, A Grishin, Edward Mccann, Vladimir I Falko, Aaron Bostwick, Eli RotenbergAbstract:We theoretically show how Constant-Energy maps of the angle-resolved photoemission intensity can be used to test wave function symmetry in graphene. For monolayer graphene, we demonstrate that the observed anisotropy of angle-resolved photoelectron spectroscopy spectra is a manifestation of what has been recently branded as an electronic chirality. For bilayer graphene, we show that the anisotropy of the Constant-Energy maps may be used to extract information about the magnitude and sign of interlayer coupling parameters and about symmetry breaking inflicted on a bilayer by the underlying substrate.