Technical Reports
HPL-2008-194R1
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Interference channel capacity region for randomized fixed-composition codes
Chang, Cheng; Etkin, Raul; Ordentlich, Erik
HP Laboratories
HPL-2008-194R1
Keyword(s): interference channels, randomized coding, capacity region
Abstract: The random coding error exponents are studied [5], [6] for the finite alphabet interference channel (IFC) with two transmitter receiver pairs. The code words are uniform on a fixed-composition set and the decoding is optimum, as opposed to decoding based on interference cancellation, and decoding that considers the interference as additional noises. In this paper we further study the error exponents of randomized fixed-composition coding, some simple lower bounds are derived for universal decoding rules. Furthermore, we give a complete characterization of the capacity region of this coding scheme that is first proposed in [5] and [6]. It is shown that even with a sophisticated time-sharing scheme among randomized fixed-composition codes, the capacity region of the randomized fixed-composition coding is not bigger than the known Han-Kobayashi capacity region first appeared in [12]. This suggests that the average behavior of random codes are not sufficient to get new capacity regions.
15 Pages
Additional Publication Information: To be published in IEEE Transactions on Information Theory & IEEE International Symposium on Information Theory
External Posting Date: February 6, 2009 [Fulltext]. Approved for External Publication
Internal Posting Date: February 6, 2009 [Fulltext]