Rate and Power Allocation for Discrete-Rate Link Adaptation. (9th January 2008)

• Record Type: Journal Article
• Authors: Gjendemsjø, Anders; Øien, Geir E.; Holm, Henrik; Alouini, Mohamed-Slim; Gesbert, David; Hole, Kjell J.; Orten, Pål
• Other Names: Karagiannidis George K. Academic Editor.
• Is Part Of: EURASIP journal on wireless communications and networking. Volume 2008(2008)
• Publication Date: 2008-01-09
• Subjects: Wireless communication systems -- Periodicals; Signal processing -- Periodicals; 621.38405
• DOI: 10.1155/2008/394124
• Languages: English
• ISSNs: 1687-1499

Abstract

Abstract : Link adaptation, in particular adaptive coded modulation (ACM), is a promising tool for bandwidth-efficient transmission in a fading environment. The main motivation behind employing ACM schemes is to improve the spectral efficiency of wireless communication systems. In this paper, using a finite number of capacity achieving component codes, we propose new transmission schemes employing constant power transmission, as well as discrete- and continuous-power adaptation, for slowly varying flat-fading channels. We show that the proposed transmission schemes can achieve throughputs close to the Shannon limits of flat-fading channels using only a small number of codes. Specifically, using a fully discrete scheme with just four codes, each associated with four power levels, we achieve a spectral efficiency within 1 dB of the continuous-rate continuous-power Shannon capacity. Furthermore, when restricted to a fixed number of codes, the introduction of power adaptation has significant gains with respect to average spectral efficiency and probability of no transmission compared to a constant power scheme.