Abstract
The sum-capacity is studied for a K-user physically degraded Gaussian multiple-access relay channel (MARC). Decode- and-forward (DF) is shown to achieve the sum-capacity and capacity region for a subclass of degraded Gaussian MARCs in which the multiple-access link from the sources to the relay is the bottleneck link. For the remaining subclass, DF is shown to achieve the K-user sum-capacity when the sources are symmetric, i.e., they transmit with the same transmit power. The optimality of DF is conjectured for the case of asymmetric sources.
Original language | English (US) |
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Pages (from-to) | 5394-5411 |
Number of pages | 18 |
Journal | IEEE Transactions on Information Theory |
Volume | 55 |
Issue number | 12 |
DOIs | |
State | Published - Dec 2009 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Information Systems
- Computer Science Applications
- Library and Information Sciences
Keywords
- Gaussian and degraded Gaussian MARC
- Multiple-access relay channel (MARC)
- Polymatroids
- Sum-capacity