Capacity of a Class of Diamond Channels

Wei Kang; Sennur Ulukus

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arXiv · 0808.0948

Capacity of a Class of Diamond Channels

Wei Kang·Sennur Ulukus

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Abstract

We study a special class of diamond channels which was introduced by Schein in 2001. In this special class, each diamond channel consists of a transmitter, a noisy relay, a noiseless relay and a receiver. We prove the capacity of this class of diamond channels by providing an achievable scheme and a converse. The capacity we show is strictly smaller than the cut-set bound. Our result also shows the optimality of a combination of decode-and-forward (DAF) and compress-and-forward (CAF) at the noisy relay node. This is the first example where a combination of DAF and CAF is shown to be capacity achieving. Finally, we note that there exists a duality between this diamond channel coding problem and the Kaspi-Berger source coding problem.

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Wei Kang, Sennur Ulukus. 2008-08-07. Capacity of a Class of Diamond Channels. https://arxiv.org/abs/0808.0948

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