Results 231 to 240 of about 139,761 (263)

Robust Cooperative Relaying in an Amplify-and-Forward Network

2011 IEEE 73rd Vehicular Technology Conference (VTC Spring), 2011
It has been shown that cooperative communication can significantly improve performance by utilizing distributed relay nodes. In most cases, cooperative communication systems have been designed and evaluated assuming perfect channel state information (CSI).
Gubong Lim, Leonard J. Cimini Jr.
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Multicarrier HF communications with amplify-and-forward relaying

2011 IEEE 22nd International Symposium on Personal, Indoor and Mobile Radio Communications, 2011
High-frequency (HF) radio communication has been recognized as the primary means for long-range wireless communications since the advent of radio. With its unique features, HF communication continues to be used for a wide range of civilian, government and military applications as a powerful alternative to a myriad of more sophisticated communication ...
Mohammad Reza Heidarpour, Murat Uysal
openaire   +2 more sources

Distributed Amplify-and-Forward with Ring-TCM Codes

2010 7th IEEE Consumer Communications and Networking Conference, 2010
This paper proposes a new distributed Amplify-and-Forward (AF) scheme which is integrated with the Ring-Trellis Coded Modulation (TCM) codes in order to achieve both high spectral efficiency and large diversity gain. In the distributed AF scheme, more users cooperate with each other.
Li Chen 0013, Rolando A. Carrasco, Ian J. Wassell   +2 more
openaire   +1 more source

Noncoherent Detection in Amplify-and-Forward Relay Systems

IEEE GLOBECOM 2008 - 2008 IEEE Global Telecommunications Conference, 2008
In amplify-and-forward single-relay systems that employ an average relay power constraint, one-shot detection at the destination terminal is not optimal when the channel between the source and relay terminals is unknown. In this work, we derive the maximum-likelihood (ML) block noncoherent detector and show that it can be expressed as a reduced-rank ...
Maria Gkizeli, George N. Karystinos
openaire   +1 more source

Jamming in Dual-Hop Amplify-and-Forward Relaying

IEEE Transactions on Vehicular Technology, 2015
The performance of a dual-hop amplify-and-forward (AF) relaying system in the presence of a jammer is analyzed by obtaining the end-to-end outage probability for the scenario where the system is interference limited and operates in either Nakagami-0.5 or Rayleigh fading environments.
Aydin Behnad, Xianbin Wang 0001
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On Slotted Amplify-and-Forward Cooperative Diversity Schemes

2006 IEEE International Symposium on Information Theory, 2006
All previously proposed amplify-and-forward (AF) and decode-and-forward (DF) schemes do not improve with the number of relays in terms of the diversity-multiplexing tradeoff (DMT) for multiplexing gains r higher than 0.5. In this work, we study the class of slotted amplify-and-forward (SAF) schemes.
Sheng Yang 0001, Jean-Claude Belfiore
openaire   +1 more source

Flexible Amplify and Forward Relaying Protocol with Optimized Duplexing

VTC Spring 2009 - IEEE 69th Vehicular Technology Conference, 2009
In this paper we propose a novel flexible amplify and forward (AF) relaying protocol with different duplexing ratios. We show that the average throughput can be considerably improved by properly adjusting the duplex ratio. Here it is considered that the transmitted and received channel state information (CSI) are available at the relay.
Mohammad Sadegh Fazel, Reza Hoshyar, Rahim Tafazolli   +2 more
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Robust Power Allocation for Amplify-and-Forward Relay Networks

2007 IEEE International Conference on Communications, 2007
Relay power allocation has been shown to provide substantial performance gain in wireless relay networks when perfect global channel state information (CSI) is available. In this paper, we consider a more realistic scenario, where such global CSI is subject to uncertainty, and we aim to design robust power allocation protocols for both the coherent and
Tony Q. S. Quek, Moe Z. Win, Hyundong Shin, Marco Chiani   +3 more
openaire   +3 more sources

An architecture for amplify‐and‐forward cooperative systems with real modulations

International Journal of Communication Systems, 2009
AbstractThis paper proposes a simple architecture for half‐duplex cooperative systems which use amplify‐and‐forward (AF) as a relay strategy and one‐dimensional modulations for source messages. The proposed solution uses the two orthogonal channels of quadrature modulation in order to allow a node to behave simultaneously as a source and a relay.
Krikidis, Ioannis A., Krikidis, Ioannis A.   +1 more
openaire   +3 more sources

Non-orthogonal Amplify-and-Forward for block-fading channels

2008 IEEE International Symposium on Information Theory, 2008
In this paper, we deal with the amplify-and-forward (AF) cooperative strategy in slot-based block-fading environments. In contrast with previous schemes which assume a constant channel during the cooperative frame (several slots), here, we relax this constraint and assume a classical quasi-static block-fading channel (constant for one slot).
Krikidis, Ioannis A., Thompson, J., McLaughlin, S., Goertz, N., Krikidis, Ioannis A., Thompson, J., McLaughlin, S., Goertz, N.   +7 more
openaire   +3 more sources