Smart Decode-and-Forward Relaying with Polar Codes

Decode-and-forward relaying based on orthogonal complementary codes

In this note, we propose a full-duplex decode-and-forward cooperative diversity scheme based on code division with orthogonal complementary codes. We consider a simple case in which a single user is assisted by a single relay to achieve cooperative diversity. When the cooperation is full-duplex, the operational delay of the relay makes the channel asynchronous and this may cause multiple-access...

Are Amplify-and-Forward Relaying and Decode-and-Forward Relaying the Same?

Rate, Reliability, and Delay Tradeoffs for Decode-and-Forward Relaying

We extend the random coding error exponent to three common decode-and-forward schemes for the relay channel. The resulting bounds give achievable tradeoffs among rate, reliability, and delay, allowing comparison of decode-and-forward with direct transmission and other schemes in broader terms than asymptotic achievable rates alone. In contrast to the asymptotic case in which the achievable rate...

LDPC Code Design for Half-Duplex Decode-and-Forward Relaying

We propose LDPC code designs for the half-duplex relay channel. Our designs mimic the information theoretic random coding scheme for decode-and-forward relaying. An important advantage of our scheme is that it is built entirely of single-user codes that can be decoded by belief propagation. The optimization of relay LDPC code profiles presents unique challenges, which are met by using the densi...

Cooperative partial retransmission scheme in incremental decode-and-forward relaying

In this paper, we present a novel hybrid automatic repeat request (HARQ) scheme for cooperative communication systems, called cooperative partial retransmission (CPR). The method is based on the retransmission of only a fraction of the original code word by the cooperating nodes. Based on the outage analysis, we derive the theoretical throughput expressions that are compared to numerical simula...