Opportunistic space-time coding to exploit cooperative diversity in fast-fading channels

In this paper, we propose a novel scheme coined opportunistic space-time coding (OSTC) to deal with the outdated channel state information (CSI) problem for opportunistic relay selection (ORS) systems. A pair of relays, instead of a single relay, is opportunistically selected in terms of the instantaneous CSIs. Alamouti scheme, a unique space-time code achieving both full-rate and full-diversity, is applied to encode the regenerated signals at this pair of relays. To evaluate the performance, a closed-form expression of outage probability is derived for OSTC. The analytical and simulated results reveal that a full diversity on the number of cooperating relays is achieved by OSTC when using perfect CSI. In the fast-fading channels, where the outdated CSI drastically degrades the performance of ORS and reduces its diversity order to 1 (i.e., no diversity), a cooperative diversity with an order of 2 can still be achieved by the proposed scheme. Most importantly, this performance gain comes without any sacrifice in the spectral efficiency, which is the drawback of Generalized Selection Combining schemes.

[1]  Mohamed H. Ahmed,et al.  Performance Analysis of Generalized Selection Combining for Decode-and-Forward Cooperative-Diversity Networks , 2010, 2010 IEEE 72nd Vehicular Technology Conference - Fall.

[2]  David Haccoun,et al.  Impact of Outdated Relay Selection on the Capacity of AF Opportunistic Relaying Systems with Adaptive Transmission over Non-Identically Distributed Links , 2011, IEEE Transactions on Wireless Communications.

[3]  Sami Muhaidat,et al.  Performance Analysis of Relay Selection With Feedback Delay and Channel Estimation Errors , 2011, IEEE Signal Processing Letters.

[4]  Srikrishna Bhashyam,et al.  Using delayed feedback for antenna selection in MIMO systems , 2009, IEEE Transactions on Wireless Communications.

[5]  Gonzalo Seco-Granados,et al.  Opportunistic relay selection with outdated CSI: outage probability and diversity analysis , 2009, IEEE Transactions on Wireless Communications.

[6]  Siavash M. Alamouti,et al.  A simple transmit diversity technique for wireless communications , 1998, IEEE J. Sel. Areas Commun..

[7]  Hyundong Shin,et al.  Cooperative Communications with Outage-Optimal Opportunistic Relaying , 2007, IEEE Transactions on Wireless Communications.

[8]  Xiaodai Dong,et al.  Opportunistic Multiple Relay Selection With Outdated Channel State Information , 2012, IEEE Transactions on Vehicular Technology.

[9]  David Haccoun,et al.  Capacity Analysis of Opportunistic Relaying in Cooperative Systems with Outdated Channel Information , 2010, IEEE Communications Letters.

[10]  Mohamed-Slim Alouini,et al.  Outage probability of diversity systems over generalized fading channels , 2000, IEEE Trans. Commun..

[11]  David Haccoun,et al.  On the Performance of AF Opportunistic Relaying over Non-identically Distributed Links with Outdated CSI , 2013, IEEE Wireless Communications Letters.

[12]  David Haccoun,et al.  Capacity of Amplify-and-Forward Selective Relaying With Adaptive Transmission Under Outdated Channel Information , 2011, IEEE Transactions on Vehicular Technology.

[13]  Sungsoo Park,et al.  Performance Analysis of Opportunistic Relaying Scheme with Outdated Channel Information , 2013, IEEE Trans. Wirel. Commun..

[14]  Aggelos Bletsas,et al.  A simple Cooperative diversity method based on network path selection , 2005, IEEE Journal on Selected Areas in Communications.

[15]  Gregory W. Wornell,et al.  Distributed space-time-coded protocols for exploiting cooperative diversity in wireless networks , 2003, IEEE Trans. Inf. Theory.

[16]  Xiaodai Dong,et al.  Unified analysis of generalized selection combining with normalized threshold test per branch , 2006, IEEE Transactions on Wireless Communications.

[17]  Elza Erkip,et al.  User cooperation diversity. Part I. System description , 2003, IEEE Trans. Commun..

[18]  Sami Muhaidat,et al.  Effect of Feedback Delay on the Performance of Cooperative Networks with Relay Selection , 2011, IEEE Transactions on Wireless Communications.