Diversity multiplexing tradeoff of asynchronous cooperative relay networks

Krishnakumar, R.N.; Naveen, Naganaboina; Sreeram, K.; Kumar, P. Vijay

doi:10.1109/allerton.2008.4797542

Cited by 6 publications

(4 citation statements)

References 17 publications

(26 reference statements)

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“…In this line of thought, the author of [6] derived the diversity-multiplexing tradeoff curve of two asynchronous cooperative diversity schemes and showed that they achieve the same performance as the synchronous Space-Time coded scheme. In [11], the authors considered two different models of asynchronous cooperative relay networks and propose a variant of the Slotted Amplify and Forward (SAF) protocol which asymptotically achieves the transmit diversity bound for both these models.…”

Section: Introductionmentioning

confidence: 99%

Outage probability and power optimization for asynchronous cooperative networks

Nahas

Saadani

Hachem

2010

2010 17th International Conference on Telecommunications

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In wireless cooperative networks, the asynchronism between the relays can be a source of diversity which is similar in its essence to the multipath diversity of frequency selective channels. In this context, an asynchronous two-relay cooperative wireless network using the Decode-and-Forward protocol is studied. Two strategies for relay coding are studied: independent coding and repetition coding. The outage probability in the high Signal to Noise Ratio (SNR) regime is derived for different relative delays between the two relays. An optimization of the power allocation is given to improve the network performance. We show that the use of independent coding by the asynchronous relays gives better outage probability performance.

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Section: Introductionmentioning

confidence: 99%

Outage probability and power optimization for asynchronous cooperative networks

Nahas

Saadani

Hachem

2010

2010 17th International Conference on Telecommunications

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“…It is shown that the same DMT performance as that of the corresponding synchronous network is achieved. In [19], under the assumption of having integer delays, two different models of asynchronism in a cooperative relay network with at least two relays are considered. For each model, a variant of the slotted amplify-and-forward (SAF) relaying protocol [20] is proposed which asymptotically achieves the transmit diversity bound in the absence of a direct source-destination link.…”

Section: Introductionmentioning

confidence: 99%

“…For each model, a variant of the slotted amplify-and-forward (SAF) relaying protocol [20] is proposed which asymptotically achieves the transmit diversity bound in the absence of a direct source-destination link. In the presence of this link, it is shown in [21] that the SAF protocol is asymptotically optimal under both models of asynchronism. It is worth nothing that in the SAF protocol, the relays are assumed to be isolated from each other which is in fact often unrealistic.…”

Section: Introductionmentioning

confidence: 99%

“…Similar to [22], we let the source and the relays to transmit over asymmetric portions of a cooperative frame in order to maximize the diversity gain at each multiplexing gain and we avoid the cooperation whenever it reduces the diversity gain compared to the case that source transmits alone. In difference with [21], we consider the more practical amplify-and-forward (AF) and decode-and-forward (DF) types protocols with real (not integer) asynchronous delays and examine the effect of the asynchronism on the DMT of the system from both the theoretical and the practical points of views.…”

Section: Introductionmentioning

confidence: 99%

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D-MG Tradeoff of DF and AF Relaying Protocols over Asynchronous PAM Cooperative Networks

Torbatian,

Damen

2009

Preprint

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The diversity multiplexing tradeoff of a general two-hop asynchronous cooperative network is examined for various relaying protocols such as non-orthogonal selection decode-and-forward (NSDF), orthogonal selection decodeand-forward (OSDF), non-orthogonal amplify-and-forward (NAF), and orthogonal amplify-and-forward (OAF). The transmitter nodes are assumed to send pulse amplitude modulation (PAM) signals asynchronously, in which information symbols are linearly modulated by a shaping waveform to be sent to the destination. We consider two different cases with respect to the length of the shaping waveforms in the time domain. In the theoretical case where the shaping waveforms with infinite time support are used, it is shown that asynchronism does not affect the DMT performance of the system and the same DMT as that of the corresponding synchronous network is obtained for all the aforementioned protocols. In the practical case where finite length shaping waveforms are used, it is shown that better diversity gains can be achieved at the expense of bandwidth expansion. In the decode-andforward (DF) type protocols, the asynchronous network provides better diversity gains than those of the corresponding synchronous network throughout the range of the multiplexing gain. In the amplify-and-forward (AF) type protocols, the asynchronous network provides the same DMT as that of the corresponding synchronous counterpart under the OAF protocol; however, a better diversity gain is achieved under the NAF protocol throughout the range of the multiplexing gain. In particular, in the single relay asynchronous network, the NAF protocol provides the same DMT as that of the 2 × 1 multiple-input single-output (MISO) channel.

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