Capacity of a Class of Diamond Channels
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.
- Publication:
-
arXiv e-prints
- Pub Date:
- August 2008
- DOI:
- 10.48550/arXiv.0808.0948
- arXiv:
- arXiv:0808.0948
- Bibcode:
- 2008arXiv0808.0948K
- Keywords:
-
- Computer Science - Information Theory;
- H.1.1
- E-Print:
- 15 pages, 3 figures, submitted to IEEE Trans. on Information Theory