TY - JOUR

T1 - Randomized space-time coding for distributed cooperative communication

AU - Sirkeci-Mergen, Birsen

AU - Scaglione, Anna

N1 - Funding Information:
Manuscript received August 18, 2005; revised January 14, 2007. This work was supported in part by the National Science Foundation by Grant ITR CCR-0428427 and by the Office of Naval Research (ONR) under contract N00014-00-1-0564. The material in this paper was presented in part at the SPAWC-2005, ICC-2006 and ICASSP-2006. The associate editor coordinating the review of this manuscript and approving it for publication was Prof. Javier Garcia-Frias.

PY - 2007/10

Y1 - 2007/10

N2 - We study the design of distributed space-time codes for cooperative communication. We assume that each node is equipped with a single antenna; however, to obtain diversity and coding gains, the cooperating nodes act as elements of a multiantenna system. With few exceptions, most of the literature on the subject proposes coding rules in which each node emulates a predetermined antenna of a multiantenna system. Since the nodes need to know their specific antenna index, either internode communication or a central control unit is required. Our design objective is to obtain diversity and coding gains while eliminating the need for code or antenna allocation. We achieve our objective by introducing novel randomized strategies that decentralize the transmission of a space time code from a set of distributed relays. Our simple idea is to let each node transmit an independent random linear combination of the codewords that would have been transmitted by all the elements of a multiantenna system. In addition to introducing this new class of designs, we fully characterize the diversity order of the corresponding symbol error probability and also analyze how the performance is linked to different choices of the statistics of the random coefficients. We show that the proposed scheme achieves full diversity (N) if N < L, where N is the number of transmitters and L is the number of antennas assumed in the underlying space-time code structure. The diversity order L is achieved if N > L. Interestingly, in certain cases (e.g., N=L=2), we show that the achieved diversity order is fractional (d*=1.5)!

AB - We study the design of distributed space-time codes for cooperative communication. We assume that each node is equipped with a single antenna; however, to obtain diversity and coding gains, the cooperating nodes act as elements of a multiantenna system. With few exceptions, most of the literature on the subject proposes coding rules in which each node emulates a predetermined antenna of a multiantenna system. Since the nodes need to know their specific antenna index, either internode communication or a central control unit is required. Our design objective is to obtain diversity and coding gains while eliminating the need for code or antenna allocation. We achieve our objective by introducing novel randomized strategies that decentralize the transmission of a space time code from a set of distributed relays. Our simple idea is to let each node transmit an independent random linear combination of the codewords that would have been transmitted by all the elements of a multiantenna system. In addition to introducing this new class of designs, we fully characterize the diversity order of the corresponding symbol error probability and also analyze how the performance is linked to different choices of the statistics of the random coefficients. We show that the proposed scheme achieves full diversity (N) if N < L, where N is the number of transmitters and L is the number of antennas assumed in the underlying space-time code structure. The diversity order L is achieved if N > L. Interestingly, in certain cases (e.g., N=L=2), we show that the achieved diversity order is fractional (d*=1.5)!

KW - Cooperative transmission

KW - Distributed networks

KW - Diversity

KW - Space-time coding

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U2 - 10.1109/TSP.2007.896061

DO - 10.1109/TSP.2007.896061

M3 - Article

AN - SCOPUS:35148841393

SN - 1053-587X

VL - 55

SP - 5003

EP - 5017

JO - IEEE Transactions on Signal Processing

JF - IEEE Transactions on Signal Processing

IS - 10

ER -