Next Article in Journal
On Finding Two Posets that Cover Given Linear Orders
Previous Article in Journal
Can People Really Do Nothing? Handling Annotation Gaps in ADL Sensor Data
Previous Article in Special Issue
A Finite Regime Analysis of Information Set Decoding Algorithms
Open AccessArticle

A New Coding Paradigm for the Primitive Relay Channel

1
Institute of Science and Technology (IST) Austria, 3400 Klosterneuburg, Austria
2
Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
3
School of Computer and Communication Sciences, EPFL, CH-1015 Lausanne, Switzerland
*
Author to whom correspondence should be addressed.
This paper is an extended version of our paper published in 2018 IEEE International Symposium on Information Theory (ISIT 2018), Vail, CO, USA, 17–22 June 2018.
Algorithms 2019, 12(10), 218; https://doi.org/10.3390/a12100218
Received: 18 June 2019 / Revised: 2 October 2019 / Accepted: 14 October 2019 / Published: 18 October 2019
(This article belongs to the Special Issue Coding Theory and Its Application)
We consider the primitive relay channel, where the source sends a message to the relay and to the destination, and the relay helps the communication by transmitting an additional message to the destination via a separate channel. Two well-known coding techniques have been introduced for this setting: decode-and-forward and compress-and-forward. In decode-and-forward, the relay completely decodes the message and sends some information to the destination; in compress-and-forward, the relay does not decode, and it sends a compressed version of the received signal to the destination using Wyner–Ziv coding. In this paper, we present a novel coding paradigm that provides an improved achievable rate for the primitive relay channel. The idea is to combine compress-and-forward and decode-and-forward via a chaining construction. We transmit over pairs of blocks: in the first block, we use compress-and-forward; and, in the second block, we use decode-and-forward. More specifically, in the first block, the relay does not decode, it compresses the received signal via Wyner–Ziv, and it sends only part of the compression to the destination. In the second block, the relay completely decodes the message, it sends some information to the destination, and it also sends the remaining part of the compression coming from the first block. By doing so, we are able to strictly outperform both compress-and-forward and decode-and-forward. Note that the proposed coding scheme can be implemented with polar codes. As such, it has the typical attractive properties of polar coding schemes, namely, quasi-linear encoding and decoding complexity, and error probability that decays at super-polynomial speed. As a running example, we take into account the special case of the erasure relay channel, and we provide a comparison between the rates achievable by our proposed scheme and the existing upper and lower bounds. View Full-Text
Keywords: primitive relay channel; compress-and-forward; decode-and-forward; chaining construction primitive relay channel; compress-and-forward; decode-and-forward; chaining construction
Show Figures

Figure 1

MDPI and ACS Style

Mondelli, M.; Hassani, S.H.; Urbanke, R. A New Coding Paradigm for the Primitive Relay Channel. Algorithms 2019, 12, 218.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop