Results 211 to 220 of about 134,511 (264)

Improvements in broadband feed‐forward amplifiers

Microwave and Optical Technology Letters, 1996
Some changes in the traditional feed-forward amplifier topology are introduced, resulting in an improved broadband operation with more than 25 dB canceling of intermodulation product levels. An outline of the main design streps is presented, together with the measurements made on a prototype. ©1996 John Wiley & Sons, Inc.
Mauro de Lima Coimbra, Rui Fragassi Souza   +1 more
openaire   +1 more source

Amplify-and-forward with partial relay selection

IEEE Communications Letters, 2008
This letter offers a statistical analysis of the basic two-hop Amplify-and-Forward link, where the relay node is selected based on instantaneous and partial knowledge of the channel. In contrast with previously reported work, where relay selection requires global knowledge (2 hops) of the relaying link, the problem considered is interesting in ...
Krikidis, Ioannis A., Thompson, J., McLaughlin, S., Goertz, N., Krikidis, Ioannis A., Thompson, J., McLaughlin, S., Goertz, N.   +7 more
openaire   +2 more sources

Adaptive Amplify-and-Forward Cooperative Channel

2007 IEEE International Symposium on Information Theory, 2007
In this work, we propose an amplify-and- forward (AF) protocol based on a new selection criterion, a function of the instantaneous capacities of all possible transmission schemes (with or without cooperation). The outage probability and the simulation results show that the new Adaptive AF protocol has better performance than the best known AF protocol (
Charlotte Hucher, Ghaya Rekaya-Ben Othman, Jean-Claude Belfiore   +2 more
openaire   +1 more source

Diversity in relaying protocols with amplify and forward

GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489), 2004
We examine a network consisting of one source, one destination and two amplifying and forwarding relays and consider a scenario in which destination and relays can have various processing limitations. For all possible diversity combining schemes at the relays and at the destination, we find diversity order results analytically and confirm our findings ...
Melda Yuksel, Elza Erkip
openaire   +1 more source

Lifetime Maximization for Amplify-and-Forward Cooperative Networks

2007 IEEE Wireless Communications and Networking Conference, 2007
Joint relay-selection and power-allocation strategies are devised to prolong the lifetime of amplify-and-forward (AF) cooperative networks. Lifetime is defined as the time duration within which the desired signal-to-noise ratio (SNR) at the destination is met with a certain probability. Based on selective relaying, we propose three strategies that take
Wan-Jen Huang, Yao-Win Peter Hong, C.-C. Jay Kuo   +2 more
openaire   +1 more source

Nonlinear Amplifier Distortion in Cooperative Amplify-and-Forward OFDM Systems

2009 IEEE Wireless Communications and Networking Conference, 2009
This paper studies receiver techniques for nonlinear amplifier distortion compensation in an OFDM relay-assisted cooperative communication system. The system model includes a nonlinear amplifier at the amplify-and-forward relay, modeled as a solid state power amplifier (SSPA).
Victor del Razo, Taneli Riihonen, Fernando H. Gregorio, Stefan Werner 0001, Risto Wichman   +4 more
openaire   +1 more source

Performance of Amplify-and-Forward and Decode-and-Forward Relays in LTE-Advanced

2009 IEEE 70th Vehicular Technology Conference Fall, 2009
Current broadband wireless networks are characterized by large cell sizes. Yet, even in advanced networks, users on the cell edge will face relatively low Signal-to- Interference-plus-Noise-Ratio (SINR). An attractive solution for this problem is provided by multi-hop technologies.
Abdallah Bou Saleh, Taneli Riihonen, Jyri Hämäläinen, Simone Redana, Bernhard Raaf, Risto Wichman   +5 more
openaire   +1 more source

An Amplify-and-Forward architecture for low spectral efficiencies

2009 IEEE International Symposium on Circuits and Systems, 2009
This 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. We prove that
Krikidis, Ioannis A., Krikidis, Ioannis A.   +1 more
openaire   +2 more sources

Design of limiting amplifier models for nonlinear amplify-and-forward distributed estimation

2013 18th International Conference on Digital Signal Processing (DSP), 2013
This paper describes the design of limiting amplifier models to be used in the implementation of non-linear amplify-and-forward distributed estimation systems. The use of nonlinear amplifiers in amplify-and-forward distributed estimation can yield significant gains in sensor power efficiency compared to the more conventional linear amplifiers.
Robert W. Santucci, Mahesh K. Banavar, Andreas Spanias, Cihan Tepedelenlioglu   +3 more
openaire   +1 more source

Linear detection for the nonorthogonal amplify and forward protocol

IEEE Transactions on Wireless Communications, 2009
In this paper, we present three new detection schemes for the nonorthogonal amplify and forward (NAF) protocol in a cooperative diversity system based on a multiuser detection approach, namely, a channel inversion type detector, a maximal-ratio combining (MRC) type detector, and a biased maximum likelihood (ML) detector. The decision variables in these
Aakanksha Chowdhery, Ranjan K. Mallik
openaire   +1 more source