Variable-power discrete-rate adaptive modulation with orthogonal space-time block coding for Nakagami-m fading channels

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)22_Publication in policy or professional journal

View graph of relations


Related Research Unit(s)


Original languageEnglish
Pages (from-to)16-24
Journal / PublicationEuropean Transactions on Telecommunications
Issue number1
Publication statusPublished - Jan 2012


The performance analysis of a space-time coded multiple-input and multiple-output system with variable-power adaptive modulation over Nakagami-m fading channels is presented. The optimum switching thresholds for attaining maximum spectrum efficiency (SE) subject to a target bit error rate (BER) and an average power constraint are derived. The existence and uniqueness of the Lagrange multiplier used in the constrained optimization are discussed. The probability density functions of instantaneous signal-to-noise ratio for both perfect and imperfect channel state information are derived, which lead to deriving closed-form SE and BER expressions. Simulation results show that the theoretical analysis and simulation are in good agreement. The variable-power adaptive modulation with space-time coding provides SE better than the constant power counterpart, and it has performance degradation in SE and BER for imperfect channel state information. Copyright © 2011 John Wiley & Sons, Ltd.

Research Area(s)

  • Adaptive modulation, Imperfect CSI, MIMO, Nakagami fading, Space-time block code, Variable power