122 research outputs found
New Phase Transitions in Optimal States for Memory Channels
We investigate the question of optimal input ensembles for memory channels
and construct a rather large class of Pauli channels with correlated noise
which can be studied analytically with regard to the entanglement of their
optimal input ensembles. In a more detailed study of a subclass of these
channels, the complete phase diagram of the two-qubit channel, which shows
three distinct phases is obtained. While increasing the correlation generally
changes the optimal state from separable to maximally entangled states, this is
done via an intermediate region where both separable and maximally entangled
states are optimal. A more concrete model, based on random rotations of the
error operators which mimic the behavior of this subclass of channels is also
presented.Comment: 13 pages, Late
Building Space Time Block Codes with set partitioning for three transmit antennas: application to STTC Codes
Publication in the conference proceedings of EUSIPCO, Florence, Italy, 200
Performance analysis of a cooperative multiple access relaying scheme
International audienc
Simple precoding algorithms using Gram-Schmidt orthonormalization process for multiuser relay communications with optimized power allocation
International audienc
Cooperative beamforming for multi-user multi-relay networks based on second-order statistics of channel state information
International audienc
Semi-analytic Approach To Evaluate Performance of a Precoded Multiuser Cooperative Scheme
International audienc
Optimized low density parity check codes designs for half duplex relay channels
International audienc
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