The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
Yong-hoon Lee - One of the best experts on this subject based on the ideXlab platform.
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VTC Spring - Amplify-Forward Relays with Superimposed Pilot Signals for Frequency-Selective Fading Channels
VTC Spring 2009 - IEEE 69th Vehicular Technology Conference, 2009Co-Authors: Haksoo Kim, Sungho Choi, Youngchul Sung, Yong-hoon LeeAbstract:In this paper, a new amplify-and-forward (AF) relay systems using superimposed pilot Signals is proposed for frequency selective fading channel environments. In the proposed scheme, the relay superimposes an additional pilot sequence on the received Signal from the source, and forwards the combined Signal to the destination. The superimposed pilot Signal in this way enables the destination node to estimate the channel between the relay and destination (R-D), and this channel information is used to process the received Signal at the destination optimally; the noise correlation due to the frequency selective fading in the R-D channel is whitened. The optimal power ratio of the superimposed pilot to the Incoming Signal at the relay is obtained via simulations, and it is shown under frequency selective channel environments that the proposed scheme yields better bit-error- rate (BER) performance than the conventional method where all relay power is allocated only to the Incoming Signal.
Haksoo Kim - One of the best experts on this subject based on the ideXlab platform.
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VTC Spring - Amplify-Forward Relays with Superimposed Pilot Signals for Frequency-Selective Fading Channels
VTC Spring 2009 - IEEE 69th Vehicular Technology Conference, 2009Co-Authors: Haksoo Kim, Sungho Choi, Youngchul Sung, Yong-hoon LeeAbstract:In this paper, a new amplify-and-forward (AF) relay systems using superimposed pilot Signals is proposed for frequency selective fading channel environments. In the proposed scheme, the relay superimposes an additional pilot sequence on the received Signal from the source, and forwards the combined Signal to the destination. The superimposed pilot Signal in this way enables the destination node to estimate the channel between the relay and destination (R-D), and this channel information is used to process the received Signal at the destination optimally; the noise correlation due to the frequency selective fading in the R-D channel is whitened. The optimal power ratio of the superimposed pilot to the Incoming Signal at the relay is obtained via simulations, and it is shown under frequency selective channel environments that the proposed scheme yields better bit-error- rate (BER) performance than the conventional method where all relay power is allocated only to the Incoming Signal.
George Guekos - One of the best experts on this subject based on the ideXlab platform.
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Optical spectral inversion without frequency shift by four-wave mixing using two pumps with orthogonal polarization
IEEE Photonics Technology Letters, 1998Co-Authors: Antonio Mecozzi, Giampiero Contestabile, Faustino Martelli, L. Graziani, A. D'ottavi, Paolo Spano, R. Dall'ara, J. Eckner, F. Girardin, George GuekosAbstract:We propose a method to obtain spectral inversion of a Signal without shifting its frequency. We use four-wave mixing (FWM) in a semiconductor optical amplifier (SOA) with two pumps of orthogonal polarization. A conjugate field is generated with a polarization orthogonal to that of the Incoming Signal and is selected at the amplifier output by a polarizer. Using a commercially available pig-tailed SOA of 1.5-mm length, we obtain after the polarizer 21.5 dB of intensity ratio between conjugate and amplified Incoming Signal.
Youngchul Sung - One of the best experts on this subject based on the ideXlab platform.
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VTC Spring - Amplify-Forward Relays with Superimposed Pilot Signals for Frequency-Selective Fading Channels
VTC Spring 2009 - IEEE 69th Vehicular Technology Conference, 2009Co-Authors: Haksoo Kim, Sungho Choi, Youngchul Sung, Yong-hoon LeeAbstract:In this paper, a new amplify-and-forward (AF) relay systems using superimposed pilot Signals is proposed for frequency selective fading channel environments. In the proposed scheme, the relay superimposes an additional pilot sequence on the received Signal from the source, and forwards the combined Signal to the destination. The superimposed pilot Signal in this way enables the destination node to estimate the channel between the relay and destination (R-D), and this channel information is used to process the received Signal at the destination optimally; the noise correlation due to the frequency selective fading in the R-D channel is whitened. The optimal power ratio of the superimposed pilot to the Incoming Signal at the relay is obtained via simulations, and it is shown under frequency selective channel environments that the proposed scheme yields better bit-error- rate (BER) performance than the conventional method where all relay power is allocated only to the Incoming Signal.
Sungho Choi - One of the best experts on this subject based on the ideXlab platform.
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VTC Spring - Amplify-Forward Relays with Superimposed Pilot Signals for Frequency-Selective Fading Channels
VTC Spring 2009 - IEEE 69th Vehicular Technology Conference, 2009Co-Authors: Haksoo Kim, Sungho Choi, Youngchul Sung, Yong-hoon LeeAbstract:In this paper, a new amplify-and-forward (AF) relay systems using superimposed pilot Signals is proposed for frequency selective fading channel environments. In the proposed scheme, the relay superimposes an additional pilot sequence on the received Signal from the source, and forwards the combined Signal to the destination. The superimposed pilot Signal in this way enables the destination node to estimate the channel between the relay and destination (R-D), and this channel information is used to process the received Signal at the destination optimally; the noise correlation due to the frequency selective fading in the R-D channel is whitened. The optimal power ratio of the superimposed pilot to the Incoming Signal at the relay is obtained via simulations, and it is shown under frequency selective channel environments that the proposed scheme yields better bit-error- rate (BER) performance than the conventional method where all relay power is allocated only to the Incoming Signal.
