On the achievable diversity-multiplexing tradeoff in half-duplex cooperative channels

By Kambiz Azarian, Hesham El Gamal, Philip Schniter. IEEE Transactions on Information Theory, 2005

1,192 citations recorded by the source corpus.

We propose novel cooperative transmission protocols for delay-limited coherent fading channels consisting of N (half-duplex and single-antenna) partners and one cell site. In our work, we differentiate between the relay, cooperative broadcast (down-link), and cooperative multiple-access (CMA) (up-link) channels. The proposed protocols are evaluated using Zheng-Tse diversity-multiplexing tradeoff. For the relay channel, we investigate two classes of cooperation schemes; namely, amplify and forward (AF) protocols and decode and forward (DF) protocols. For the first class, we establish an upper bound on the achievable diversity-multiplexing tradeoff with a single relay. We then construct a new AF protocol that achieves this upper bound. The proposed algorithm is then extended to the general case with (N-1) relays where it is shown to outperform the space-time coded protocol of Laneman and Wornell without requiring decoding/encoding at the relays. For the class of DF protocols, we develop a dynamic decode and forward (DDF) protocol that achieves the optimal tradeoff for multiplexing gains 0lesrles1/N. Furthermore, with a single relay, the DDF protocol is shown to dominate the class of AF protocols for all multiplexing gains. The superiority of the DDF protocol is shown to be more significant in the cooperative broadcast channel. The situation is reversed in the CMA channel where we propose a new AF protocol that achieves the optimal tradeoff for all multiplexing gains. A distinguishing feature of the proposed protocols in the three scenarios is that they do not rely on orthogonal subspaces, allowing for a more efficient use of resources. In fact, using our results one can argue that the suboptimality of previously proposed protocols stems from their use of orthogonal subspaces rather than the half-duplex constraint.

Subfields: Computer Networks and Communications, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/df3b3b996f7c6bba9c2a77d9a08801385636338e

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Citations in the corpus

Relay Architectures for 3GPP LTE-Advanced (2009, background): “In research, relays are often assumed to be half-duplex (they can either send or receive but not at the same time) or full-duplex (can send and receive at the same time) [19].”
Full length article: On coding for reliable communication over packet networks (2008, neutral): “e or more packets are received—sometimes referred to a s multipacket reception capability [33]. It may even be the case that physical-layer cooperative schemes, such as those presented in [34], [35], [36], are used, where nodes that are not transmitting packets are used to assist LIDS PUBLICATION #2”
Hybrid Full-Duplex/Half-Duplex Relaying with Transmit Power Adaptation (2011, background): “The BS may transmit new data during RN transmission if the UE applies extra techniques for decoding the superimposed transmissions [7], [12].”
An overview of limited feedback in wireless communication systems (2008, background): “can make simple orthogonal decode-and-forward strategies competitive with dynamic decode-and-forward [15].”
Cooperative Jamming for Secure Communications in MIMO Relay Networks (2011, background): “[27] and [28]) at the relay since independent codebooks are expected to result in smaller secrecy rates when the encoding schemes and relay protocols are public information [26].”
The Relay–Eavesdropper Channel: Cooperation for Secrecy (2006, background): “The relay channel without security constraints was studied under various scenarios [4]–[12].”
Using Orthogonal and Quasi-Orthogonal Designs in Wireless Relay Networks (2007, methodology): “The authors are with the Department of Electrical Engineering and Computer Science, University of California, Irvine, Irvine, CA 92697 USA (e-mail: yjing@uci.edu; hamidj@uci.edu).”
Multiple-Antenna Cooperative Wireless Systems: A Diversity–Multiplexing Tradeoff Perspective (2007, methodology): “This idea is also used in [39] to study the nonorthogonal amplify-and-forward (NAF) protocol in terms of DMT.”