D-MG tradeoff and optimal codes for a class of AF and DF cooperative communication protocols
IEEE Transactions on Information Theory
ISIT'09 Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4
Diversity and multiplexing: a fundamental tradeoff in multiple-antenna channels
IEEE Transactions on Information Theory
Distributed space-time-coded protocols for exploiting cooperative diversity in wireless networks
IEEE Transactions on Information Theory
Cooperative diversity in wireless networks: Efficient protocols and outage behavior
IEEE Transactions on Information Theory
On the achievable diversity-multiplexing tradeoff in half-duplex cooperative channels
IEEE Transactions on Information Theory
IEEE Transactions on Information Theory
Approximately universal codes over slow-fading channels
IEEE Transactions on Information Theory
Explicit Space–Time Codes Achieving the Diversity–Multiplexing Gain Tradeoff
IEEE Transactions on Information Theory
Optimal Space–Time Codes for the MIMO Amplify-and-Forward Cooperative Channel
IEEE Transactions on Information Theory
Delay-Tolerant Distributed-TAST Codes for Cooperative Diversity
IEEE Transactions on Information Theory
Diversity–Multiplexing Tradeoff of Asynchronous Cooperative Diversity in Wireless Networks
IEEE Transactions on Information Theory
IEEE Transactions on Information Theory
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An asynchronous cooperative network where different time delays exist among nodes is considered in this paper. Assuming the signals are OFDM modulated, it is first shown that the diversity-multiplexing tradeoff (DMT) achieved by the non-orthogonal selection decode-and-forward (NSDF) protocol for this network is the same as that for the synchronous one. In contrast to the complicated approximately universal "matrix" codes, where each relay uses a different codebook, a systematic construction of an extremely simple "vector" code is proposed. Given the transmitted codeword vector, this vector will be used by all nodes in the network for signal transmission; hence, the proposed coding scheme greatly reduces the complexity of relay deployment and decoding. Furthermore, it is proven that the proposed scheme is optimal in terms of the DMT of the NSDF protocol for this asynchronous network, provided all time delays are distinct. Finally, it is shown that the proposed code design can be extended to the orthogonal selection decode-and-forward protocol and remains to be DMT optimal.