Interplay Between Optimal Selection Scheme, Selection Criterion, and Discrete Rate Adaptation in Opportunistic Wireless Systems

Mehta, Neelesh B and Talak, Rajat and Suresh, Ananda T (2013) Interplay Between Optimal Selection Scheme, Selection Criterion, and Discrete Rate Adaptation in Opportunistic Wireless Systems. In: IEEE TRANSACTIONS ON COMMUNICATIONS, 61 (7). pp. 2735-2745.

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Abstract

An opportunistic, rate-adaptive system exploits multi-user diversity by selecting the best node, which has the highest channel power gain, and adapting the data rate to selected node's channel gain. Since channel knowledge is local to a node, we propose using a distributed, low-feedback timer backoff scheme to select the best node. It uses a mapping that maps the channel gain, or, in general, a real-valued metric, to a timer value. The mapping is such that timers of nodes with higher metrics expire earlier. Our goal is to maximize the system throughput when rate adaptation is discrete, as is the case in practice. To improve throughput, we use a pragmatic selection policy, in which even a node other than the best node can be selected. We derive several novel, insightful results about the optimal mapping and develop an algorithm to compute it. These results bring out the inter-relationship between the discrete rate adaptation rule, optimal mapping, and selection policy. We also extensively benchmark the performance of the optimal mapping with several timer and opportunistic multiple access schemes considered in the literature, and demonstrate that the developed scheme is effective in many regimes of interest.

Item Type:	Journal Article
Publication:	IEEE TRANSACTIONS ON COMMUNICATIONS
Publisher:	IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Additional Information:	Copyright of this article is belongs to IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Keywords:	Cross-layer design; distributed selection; discrete rate adaptation; adaptive modulation and coding; timer scheme; fading channels; multiple access; collision; net throughput
Department/Centre:	Division of Electrical Sciences > Electrical Communication Engineering
Date Deposited:	02 Oct 2013 06:04
Last Modified:	02 Oct 2013 06:04
URI:	http://eprints.iisc.ac.in/id/eprint/47361

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