dc.contributor.author Gherekhloo, Soheil dc.contributor.author Chaaban, Anas dc.contributor.author Sezgin, Aydin dc.date.accessioned 2017-01-29T13:51:37Z dc.date.available 2017-01-29T13:51:37Z dc.date.issued 2016-11-14 dc.identifier.citation Gherekhloo S, Chaaban A, Sezgin A (2017) Expanded GDoF-optimality Regime of Treating Interference as Noise in the $M\times 2$ X-Channel. IEEE Transactions on Information Theory 63: 355–376. Available: http://dx.doi.org/10.1109/TIT.2016.2628376. dc.identifier.issn 0018-9448 dc.identifier.issn 1557-9654 dc.identifier.doi 10.1109/TIT.2016.2628376 dc.identifier.uri http://hdl.handle.net/10754/622758 dc.description.abstract Treating interference as noise (TIN) as the most appropriate approach in dealing with interference and the conditions on its optimality has attracted the interest of researchers recently. However, our knowledge on necessary and sufficient conditions of TIN is restricted to a few setups with limited number of users. In this paper, we study the optimality of TIN in terms of the generalized degrees of freedom (GDoF) for a fundamental network, namely, the M× 2 X-channel. To this end, the achievable GDoF of TIN with power allocations at the transmitters is studied. It turns out that the transmit power allocation maximizing the achievable GDOF is given by on-off signaling as long as the receivers use TIN. This leads to two variants of TIN, namely, P2P-TIN and 2-IC-TIN. While in the first variant the M× 2 X-channel is reduced to a point-to-point (P2P) channel, in the second variant, the setup is reduced to a two-user interference channel in which the receivers use TIN. The optimality of these two variants is studied separately. To this end, novel genie-aided upper bounds on the capacity of the X-channel are established. The conditions on the optimality of P2P-TIN can be summarized as follows. P2P-TIN is GDoF-optimal if there exists a dominant multiple access channel or a dominant broadcast channel embedded in the X channel. Furthermore, the necessary and sufficient conditions on the GDoF-optimality of 2-IC-TIN are presented. Interestingly, it turns out that operating the M× 2 X-channel in the 2-IC-TIN mode might be still GDOF optimal, although the conditions given by Geng et al. are violated. However, 2-IC-TIN is sub-optimal if there exists a single interferer which causes sufficiently strong interference at both receivers. The comparison of the results with the state of the art shows that the GDOF optimality of TIN is expanded significantldy. dc.description.sponsorship This work was supported by the German Research Foundation, Germany, under Grant Se 1697/3. dc.publisher Institute of Electrical and Electronics Engineers (IEEE) dc.relation.url http://ieeexplore.ieee.org/document/7742969/ dc.subject Gaussian channel dc.subject generalized degrees of freedom (GDoF) dc.subject sumcapacity upper bounds dc.subject Treating interference as noise dc.subject X-channel dc.title Expanded GDoF-optimality Regime of Treating Interference as Noise in the $M\times 2$ X-Channel dc.type Article dc.contributor.department Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division dc.contributor.department Electrical Engineering Program dc.identifier.journal IEEE Transactions on Information Theory dc.contributor.institution Institute of Digital Communication Systems, Ruhr-Universität Bochum, Bochum, 44780, Germany dc.contributor.institution Ruhr-Universität Bochum, Bochum, 44780, Germany kaust.person Chaaban, Anas dc.date.published-online 2016-11-14 dc.date.published-print 2017-01
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