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Hier finden Sie wissenschaftliche Publikationen aus den FraunhoferInstituten. On the highSNR capacity of the Gaussian interference channel and new capacity bounds
 IEEE transactions on information theory 63 (2017), Nr.8, S.52665285 ISSN: 00189448 

 Englisch 
 Zeitschriftenaufsatz 
 Fraunhofer HHI () 
Abstract
The best outer bound on the capacity region of the twouser Gaussian interference channel (GIC) is known to be the intersection of regions of various bounds, including genieaided outer bounds, in which a genie provides noisy input signals to the intended receiver. The Han and Kobayashi (HK) scheme provides the best known inner bound. The rate difference between the best known lower and upper bounds on the sum capacity remains as large as 1 b/channel use, especially around g2 = P1/3, where P is the symmetric power constraint and g is the symmetric real crosschannel coefficient. In this paper, we pay attention to the moderate interference regime where g2 ∈ (max(0.086, P1/3), 1). We propose a new upperbounding technique that utilizes noisy observation of interfering signals as genie signals and applies time sharing to the genie signals at the receivers. A conditional version of the worst additive noise lemma is also introduced to derive new capacity bounds. The resulting upper (outer) bounds on the sum capacity (capacity region) are shown to be tighter than the existing bounds in a certain range of the moderate interference regime. Using the new upper bounds and the HK lower bound, we show that Rsym*= 1/2 log (gP + g1(P + 1)) characterizes the capacity of the symmetric real GIC to within 0.104 b/channel use in the moderate interference regime at any signaltonoise ratio (SNR). We further establish a highSNR characterization of the symmetric real GIC, where the proposed upper bound is at most 0.1 b far from a certain HK achievable scheme with Gaussian signalling and time sharing for g2 ∈ (0, 1]. In particular, Rsym* is achievable at high SNR by the proposed HK scheme and turns out to be the highSNR capacity at least at g2 = 0.25, 0.5. We finally point out that there are two subregimes at high SNR in the weak interference regime, where g2 ∈ (0, 1].