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Title:
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Rate-constrained Relaying: A Model for Cooperation with Limited Relay Resources |
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Author:
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Sabharwal, Ashutosh; Mitra, Urbashi
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Type:
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Journal Paper |
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Keywords:
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Relay channel; complexity; achievable rates; decode and forward; estimate and forward; amplify and forward |
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Citation:
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A. Sabharwal and U. Mitra, "Rate-constrained Relaying: A Model for Cooperation with Limited Relay Resources," IEEE Transactions on Information Theory, 2005. |
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Abstract:
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In this paper, the impact of limited resources on achievable rates in relay channels is investigated. Resource limitation is modeled as a rate constraint, Rbar, which constrains the rate at which a relay can reliably decode or source-code data. With this constraint in hand, the achievable rates for several protocols are derived and compared: decode-and-forward, estimate-and-forward, a Markovian amplify-and-forward and a hybrid scheme that combines decode-and-forward and amplify-and-forward. The key result is that the relative performance of these protocols in the unconstrained case is not maintained in rate constrained scenarios. The case of severe resource limitation (Rbar --> 0) is also considered. Previously established rates for unconstrained decode-and-forward and estimate-and-forward are re-examined in the context of optimal parameters and asymptotic performance. For most relay locations (topologies), either decode-and-forward and estimate-and-forward offers superior performance. However, for severe rate constraints, amplify-and-forward generally offers the best performance. |
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Date Published:
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2005-06-01 |
