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distributed orthogonal space-time coding: Design and outage analysis for randomized cooperation

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2007年第12期6卷 4546-4557页

作者： Savazzi, Stefano Spagnolini, Umberto Politecn Milan Dipartimento Elettr & Informat I-20133 Milan Italy

In this paper we consider a cooperative wireless network where each terminal communicates to a destination node with the aid of multiple relaying nodes. The focus is on cooperative transmission protocols that are based on the simultaneous transmission by a number of cooperating nodes. Outage performances are analyzed by assuming a distributed Randomized Orthogonal space-time coding scheme (DR-OSTC) to be employed by the relaying terminals during the transmission session. The DR-OSTC scheme requires that each cooperating node chooses randomly and independently to serve as one of the space-time virtual antennas. By avoiding any pre-defined terminal-to-codeword mapping, the random selection of the space-time codewords substantially reduces the needed control overhead with respect to other distributed space-time coding strategies simplifying the node coordination task. According to this scheme, in this paper it is tackled the problem of designing both, the minimum number of cooperating nodes M and the spatial dimension L of the space-time code matrix so as to meet a specific outage probability requirement at the destination. Outage performances are also analyzed by developing simple but effective design rules tailored for two cooperative trasmission protocols in realistic propagation environments.

关键词： distributed space-time coding cooperative diversity space-time coding design ad-hoc and sensors networks wireless networks

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distributed space-time block coding

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IEEE TRANSACTIONS ON COMMUNICATIONS 2006年第7期54卷 1195-1206页

作者： Yiu, Simon Schober, Robert Lampe, Lutz Univ British Columbia Dept Elect & Comp Engn Vancouver BC V6T 1Z4 Canada

In this paper, a new class of distributed space-time block codes (DSTBCs) is introduced. These DSTBCs are designed for wireless networks which have a large set of single-antenna relay nodes N, but at any given time only a small, a priori unknown subset of nodes S subset of N can be active. In the proposed scheme, the signal transmitted by an active relay node is the product of an information-carrying code matrix and a unique node signature vector of length N-c. It is shown that existing STBCs designed for N-c >= 2 co-located antennas are favorable choices for the code matrix, guaranteeing a diversity order of d = min{N-S, N-c} if N-s nodes are active. For the most interesting case, N-S >= N-c, the performance loss entailed by the distributed implementation is analytically characterized. Furthermore, efficient methods for the optimization of the set of signature vectors are provided. Depending on the chosen design, the proposed DSTBCs allow for low-complexity coherent, differential, and noncoherent detection, respectively. Possible applications include ad hoc and sensor networks employing decode-and-forward relaying.

关键词： ad hoc and sensor networks cooperative diversity distributed space-time coding fading channels relaying wireless networks

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Decentralized distributed space-time trellis coding

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2007年第11期6卷 3985-3993页

作者： Yiu, Simon Schober, Robert Lampe, Lutz Univ British Columbia Dept Elect & Comp Engn Vancouver BC V6T 1Z4 Canada

In this paper, we introduce a new class of distributed space-time trellis codes (DSTTCs) for wireless networks with a large set (if decode-and-forward relay nodes N. We consider the general case where each relay node is equipped with N-T antennas and the destination node is equipped with N-R antennas. It is assumed that at any given time only a small, a priori unknown subset of nodes S epsilon N is active and neither the relay nodes nor the destination node know which relay nodes are active. In the proposed scheme, each node is assigned a signature matrix and the signal transmitted by an active node is the product of the signature matrix and a space-time trellis code (STTC) matrix originally designed for N, co-located antennas. It is shown that existing full-rank STTCs designed for N-c >= 2 co-located antennas are a favorable choice for the code matrix. Two practical designs for good deterministic signature matrix sets are provided and compared with random signature matrices. If the signature matrices are properly optimized, the proposed DSTTCs achieve a diversity order of d = min{N-c N-R, NTNSNR} if N-S nodes are active. Simulation results confirm that DSTTCs yield significant performance gains over distributed space-time block codes and distributed space-time filtering. Furthermore, equipping relay nodes with a second antenna can be highly beneficial especially if only few nodes can be active at any given time.

关键词： ad hoc and sensor networks cooperative diversity distributed space-time coding fading channels relaying wireless networks

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Differential distributed space-time coding with Imperfect Synchronization

Differential Distributed Space-Time Coding with Imperfect Sy...

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IEEE Global Communications Conference

作者： M. R. Avendi Sina Poorkasmaei Hamid Jafarkhani Center for Pervasive Communications and Computing University of California

ISBN: (纸本)9781479935130

Differential distributed space-time coding (D-DSTC) has been considered to improve both diversity and data-rate in cooperative communications in the absence of channel information. However, conventionally, it is assumed that relays are perfectly synchronized in the symbol level. In practice, this assumption is easily violated due to the distributed nature of the relay networks. This paper proposes a new differential encoding and decoding process for D-DSTC systems with two relays. The proposed method is robust against synchronization errors and does not require any channel information at the destination. Moreover, the maximum possible diversity and symbol-by-symbol decoding are attained. Simulation results are provided to show the performance of the proposed method for various synchronization errors and the fact that our algorithm is not sensitive to synchronization error.

关键词： distributed space-time coding Differential encoding and decoding Synchronization error OFDM Relay networks

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distributed space-time block coding

Distributed space-time block coding

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IEEE Global Telecommunications Conference (GLOBECOM 05)

作者： Yiu, Simon Schober, Robert Lampe, Lutz Univ British Columbia Dept Elect & Comp Engn Vancouver BC V6T 1Z4 Canada

ISBN: (纸本)0780394143

关键词： ad hoc and sensor networks cooperative diversity distributed space-time coding fading channels relaying wireless networks

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distributed DIFFERENTIAL space-time coding FOR TWO-WAY RELAY NETWORKS USING ANALOG NETWORK coding

DISTRIBUTED DIFFERENTIAL SPACE-TIME CODING FOR TWO-WAY RELAY...

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21st European Signal Processing Conference (EUSIPCO)

作者： Alabed, Samer Pesavento, Marius Klein, Anja Tech Univ Darmstadt Inst Telecommun Merckstr 25 D-64283 Darmstadt Germany Tech Univ Darmstadt Commun Syst Grp D-64283 Darmstadt Germany Tech Univ Darmstadt Commun Engn Lab D-64283 Darmstadt Germany

ISBN: (纸本)9781479936878

Differential distributed space-time coding (DSTC) techniques using several transmission protocols have recently been proposed to overcome the overhead involved with the acquisition of channel state information (CSI) required for coherent processing. In this paper, a novel amplify-and- forward differential DSTC technique for two-way wireless relay networks (TWRNs) is proposed, that uses the concept of analog network coding and which does not require CSI at any node to decode the information symbols. In our transmission scheme, the relays do not waste power to transmit known information. This is achieved by combining the symbol vectors of both terminals at the relays into a single symbol vector without decoding the information symbols. Furthermore, in our scheme, the direct link between the communicating terminals can be easily incorporated to further improve the diversity gain. Simulations show a substantially improved performance in terms of bit error rate (BER) of the proposed technique as compared to the known techniques.

关键词： Two-way wireless relay networks distributed space-time coding differential space-time coding cooperative diversity analog network coding

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distributed DIFFERENTIAL space-time coding FOR TWO-WAY RELAY NETWORKS USING ANALOG NETWORK coding

DISTRIBUTED DIFFERENTIAL SPACE-TIME CODING FOR TWO-WAY RELAY...

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European Signal Processing Conference

作者： Samer Alabed Marius Pesavento Anja Klein Institute of Telecommunications Darmstadt University of Technology Merckstr. 25 64283 Darmstadt Germany

ISBN: (纸本)9781479936878

Differential distributed space-time coding (DSTC) techniques using several transmission protocols have recently been proposed to overcome the overhead involved with the acquisition of channel state information (CSI) required for coherent processing. In this paper, a novel amplify-and-forward differential DSTC technique for two-way wireless relay networks (TWRNs) is proposed, that uses the concept of analog network coding and which does not require CSI at any node to decode the information symbols. In our transmission scheme, the relays do not waste power to transmit known information. This is achieved by combining the symbol vectors of both terminals at the relays into a single symbol vector without decoding the information symbols. Furthermore, in our scheme, the direct link between the communicating terminals can be easily incorporated to further improve the diversity gain. Simulations show a substantially improved performance in terms of bit error rate (BER) of the proposed technique as compared to the known techniques.

关键词： Two-way wireless relay networks distributed space-time coding differential space-time coding cooperative diversity analog network coding

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Optimal Coherent Combining Scheme for Relay Networks

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WIRELESS PERSONAL COMMUNICATIONS 2016年第3期88卷 575-585页

作者： Wang, Jin Shu, Feng Huang, Xiaohui Wang, Yimeng Nanjing Univ Sci & Technol Sch Elect & Opt Engn Nanjing 210094 Jiangsu Peoples R China China Res Inst Radiowave Propagat Natl Key Lab Electromagnet Environm Qingdao 266107 Peoples R China Fujian Agr & Forestry Univ Coll Comp & Informat Sci Fuzhou 35002 Peoples R China

To achieve more reliable performance at relay networks, an optimal coherent combining scheme, called maximum rate (Max-Rate), is proposed. By making use of skills in convex optimization and matrix theory, we derive the closed-form expression for the proposed Max-Rate. From simulation results, it follows that the proposed optimal combining scheme achieves substantial signal-to-noise ratio gains over existing schemes such as distributed space-time block coding, maximum ratio combining and their combination for a given symbol error rate.

关键词： Coherent combining Maximum rate combining distributed space-time coding Maximum ratio combining Symbol error rate

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Multi-Source Cooperative Communication With Opportunistic Interference Cancelling Relays

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IEEE TRANSACTIONS ON COMMUNICATIONS 2015年第11期63卷 4086-4096页

作者： Argyriou, Antonios Univ Thessaly Dept Elect & Comp Engn Volos 38221 Greece

In this paper, we present a multi-user cooperative protocol for wireless networks. Two sources transmit simultaneously their information blocks and relays employ opportunistically successive interference cancellation (SIC) in an effort to decode them. An adaptive decode/amplify-and-forward scheme is applied at the relays to the decoded blocks or their sufficient statistic if decoding fails. The main feature of the protocol is that SIC is exploited in a network since more opportunities arise for each block to be decoded as the number of used relays N-RU is increased. This feature leads to benefits in terms of diversity and multiplexing gains that are proven with the help of an analytical outage model and a diversity-multiplexing tradeoff (DMT) analysis. The performance improvements are achieved without any network synchronization and coordination. In the final part of this work, the closed-form outage probability model is used by a novel approach for offline pre-selection of the N-RU relays, that have the best SIC performance, from a larger number of N-R nodes. The analytical results are corroborated with extensive simulations, while the protocol is compared with orthogonal and multi-user protocols reported in the literature.

关键词： Successive interference cancellation cooperative protocol multi-user communication dense wireless networks distributed space-time coding multiplexing gain

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Channel Training Design in Amplify-and-Forward MIMO Relay Networks

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2011年第10期10卷 3380-3391页

作者： Sun, Sun Jing, Yindi Univ Alberta Dept Elect & Comp Engn Edmonton AB T6G 2V4 Canada

This paper is on the channel training design for distributed space-time coding (DSTC) in multi-antenna relay networks. DSTC is shown to achieve full diversity in relay networks. To use DSTC, the receiver has to know both the channels between the relays and the receiver (Relay-Rx channels), and the channels between the transmitter and the relays (Tx-Relay channels). For the Relay-Rx channels, by sending pilot signals from the relays, the training problem can be solved using multi-input-multi-output (MIMO) training schemes. Given the knowledge of the Relay-Rx channels, to obtain estimations of the Tx-Relay channels at the receiver, DSTC is used. The linear minimum-mean-square-error (LMMSE) estimation at the receiver and the optimal pilot design that minimizes the estimation error are derived. We also investigate the requirement on the training time that can lead to full diversity in data transmission. An upper bound and a lower bound on the training time are provided. A novel training design whose training time length is adaptive to the quality of the Relay-Rx channels is also proposed. Simulations are exhibited to justify our analytical results and to show advantages of the proposed scheme over others.

关键词： Channel training LMMSE estimation MIMO relay networks cooperative diversity distributed space-time coding

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