Power adaptation for joint switched diversity and adaptive modulation schemes in spectrum sharing systems

Zied Bouida, Kamel Tourki, Ali Ghrayeb, Khalid Qaraqe, Mohamed Slim Alouini

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Under the scenario of an underlay cognitive radio network, we propose in this paper an adaptive scheme using transmit power adaptation, switched transmit diversity, and adaptive modulation in order to improve the performance of existing switching efficient schemes (SES) and bandwidth efficient schemes (BES). Taking advantage of the channel reciprocity principle, we assume that the channel state information (CSI) of the interference link is available to the secondary transmitter. This information is then used by the secondary transmitter to adapt its transmit power, modulation constellation size, and used transmit branch. The goal of this joint adaptation is to minimize the average number of switched branches and the average system delay given the fading channel conditions, the required error rate performance, and a peak interference constraint to the primary receiver. We analyze the proposed scheme in terms of the average number of branch switching, average delay, and we provide a closed-form expression of the average bit error rate (BER). We demonstrate through numerical examples that the proposed scheme provides a compromise between the SES and the BES schemes.

Original languageEnglish
Article number6244787
Pages (from-to)1482-1485
Number of pages4
JournalIEEE Communications Letters
Volume16
Issue number9
DOIs
Publication statusPublished - 2012

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Keywords

  • Adaptive modulation
  • and switched diversity
  • performance analysis
  • power adaptation
  • spectrum sharing

ASJC Scopus subject areas

  • Modelling and Simulation
  • Computer Science Applications
  • Electrical and Electronic Engineering

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