Two-User Relay Transmission with Shorter Delay

In this paper, a cooperative system with two users and one relay is considered. An amplify-and-forward relaying protocol is applied in a half duplex mode. To make the transmission delay as short as possible, the relay forwards for both users simultaneously. We consider transmission schemes with symbol rates $2/3$ to demonstrate the tradeoff among performance, delay, and symbol rate. Based on the analysis for the pairwise error probability~(PEP), an optimal precoder is proposed to achieve the full diversity and best coding gain. Simulations show that the proposed precoder can provide about one dB improvement over some conventional space-time block codes at bit error rate $10^{-4}$.

[1]  Jean-Claude Belfiore,et al.  Distributed space time codes for the Amplify-and-Forward Multiple-Access Relay channel , 2008, 2008 IEEE International Symposium on Information Theory.

[2]  Petar Popovski,et al.  Wireless network coding by amplify-and-forward for bi-directional traffic flows , 2007, IEEE Communications Letters.

[3]  Georgios B. Giannakis,et al.  Space-time diversity systems based on linear constellation precoding , 2003, IEEE Trans. Wirel. Commun..

[4]  Georgios B. Giannakis,et al.  Complex Field Network Coding for Multiuser Cooperative Communications , 2008, IEEE Journal on Selected Areas in Communications.

[5]  Emanuele Viterbo,et al.  The golden code: a 2×2 full-rate space-time code with nonvanishing determinants , 2004, IEEE Trans. Inf. Theory.

[6]  Philip Schniter,et al.  On the achievable diversity-multiplexing tradeoff in half-duplex cooperative channels , 2005, IEEE Transactions on Information Theory.

[7]  Jean-Claude Belfiore,et al.  Algebraic tools to build modulation schemes for fading channels , 1997, IEEE Trans. Inf. Theory.

[8]  J. Craig.  A new, simple and exact result for calculating the probability of error for two-dimensional signal constellations , 1991, MILCOM 91 - Conference record.

[9]  Leonard J. Cimini,et al.  Cooperative network coding in selective decode-and-forward networks with multiple source-destination pairs , 2008, 2008 42nd Annual Conference on Information Sciences and Systems.

[10]  Patrick Mitran,et al.  Variable-Rate Two-Phase Collaborative Communication Protocols for Wireless Networks , 2006, IEEE Transactions on Information Theory.

[11]  Gregory W. Wornell,et al.  Cooperative diversity in wireless networks: Efficient protocols and outage behavior , 2004, IEEE Transactions on Information Theory.

[12]  Helmut Bölcskei,et al.  Fading relay channels: performance limits and space-time signal design , 2004, IEEE Journal on Selected Areas in Communications.

[13]  Jian-Kang Zhang,et al.  The Amplify-and-Forward Half-Duplex Cooperative System: Pairwise Error Probability and Precoder Design , 2007, IEEE Transactions on Signal Processing.

[14]  Emanuele Viterbo,et al.  The golden code: a 2 x 2 full-rate space-time code with non-vanishing determinants , 2004, International Symposium onInformation Theory, 2004. ISIT 2004. Proceedings..