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arXiv · 1404.6348

A DoF-Optimal Scheme for the two-user X-channel with Synergistic Alternating CSIT

Ahmed Wagdy·Amr El-Keyi·Tamer Khattab·Mohammed Nafie
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Abstract

In this paper, the degrees of freedom (DoF) of the two-user single input single output (SISO) X-channel are investigated. Three cases are considered for the availability of channel state information at the transmitters (CSIT); perfect, delayed, and no-CSIT. A new achievable scheme is proposed to elucidate the potency of interference creation-resurrection (IRC) when the available CSIT alternates between these three cases. For some patterns of alternating CSIT, the proposed scheme achieves $4/3$ DoF, and hence, coincides with the information theoretic upper bound on the DoF of the two-user X-channel with perfect and instantaneous CSIT. The CSIT alternation patterns are investigated where the patterns that provide extraordinary synergistic gain and dissociative ones are identified.

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Ahmed Wagdy, Amr El-Keyi, Tamer Khattab, Mohammed Nafie. 2014-04-25. A DoF-Optimal Scheme for the two-user X-channel with Synergistic Alternating CSIT. https://arxiv.org/abs/1404.6348

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