On the Role of Estimate-and-Forward with
Time-Sharing in Cooperative Communications
Authors
R. Dabora, S. D. Servetto.
Status
IEEE Transactions on Information Theory; Submitted, May 2006; Revised,
October 2006.
Abstract
In this work we focus on the general relay channel. We investigate the
application of estimate-and-forward (EAF) to different scenarios.
Specifically, we consider assignments of the auxiliary random variables
that always satisfy the feasibility constraints. We first consider the
multiple relay channel and obtain an achievable rate without decoding
at the relays. We demonstrate the benefits of this result via an explicit
discrete memoryless multiple relay scenario where multi-relay EAF is
superior to multi-relay decode-and-forward (DAF). We then consider the
Gaussian relay channel with coded modulation, where we show that a
three-level quantization outperforms the Gaussian quantization commonly
used to evaluate the achievable rates in this scenario. Finally we
consider the cooperative general broadcast scenario with a multi-step
conference. We apply estimate-and-forward to obtain a general multi-step
achievable rate region. We then give an explicit assignment of the
auxiliary random variables, and use this result to obtain an explicit
expression for the single common message broadcast scenario with a
two-step conference.
R. Dabora, S. D. Servetto.
A Multi-Step Conference for Cooperative
Broadcast. In the Proceedings of the IEEE International
Symposium on Information Theory (ISIT), Seattle, WA, July 2006.