Cooperate-and-access spectrum sharing with ARQ-based primary systems

Qiang Li, See Ho Ting, Ashish Pandharipande, Mehul Motani

Research output: Contribution to journalArticleAcademicpeer-review

24 Citations (Scopus)


We consider spectrum sharing in a cognitive radio network where a secondary system co-exists with an automatic repeat-request (ARQ)-based primary system. A cooperate-and-access spectrum sharing protocol is proposed where the secondary system alternates between cooperation and access modes. In the cooperation mode, the secondary system serves as a relay to assist the primary transmission, and in return accumulates credits. The credits allow the secondary system to gain spectrum access by exploiting the ARQ retransmissions of the primary system. We show analytically that through the proposed credit system, as long as the credits accumulated in cooperation mode compensate for the degradation in primary performance during access mode, an equal or higher average throughput is achieved for the primary system than in the case without spectrum sharing, while providing spectrum access opportunities for the secondary system.

Original languageEnglish
Article number6253215
Pages (from-to)2861-2871
Number of pages11
JournalIEEE Transactions on Communications
Issue number10
Publication statusPublished - 2012

Bibliographical note

Funding Information:
Paper approved by L. K. Rasmussen, the Editor for Iterative Detection Decoding and ARQ of the IEEE Communications Society. Manuscript received October 11, 2011; revised March 16, 2012. Q. Li and S. H. Ting are with the School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639801 (e-mail: {liqi0008, shting} A. Pandharipande is with Philips Research, High Tech Campus, 5656 AE Eindhoven, Netherlands (e-mail: M. Motani is with the Department of Electrical and Computer Engineering, National University of Singapore (e-mail: This work is supported by the Singapore Ministry of Education Academic Research Fund Tier 2, MOE2009-T2-2-059. This work has been partly presented in conference proceedings [1]. Digital Object Identifier 10.1109/TCOMM.2012.072412.110680


  • ARQ
  • cognitive radios
  • Cooperative spectrum sharing
  • relay

Fingerprint Dive into the research topics of 'Cooperate-and-access spectrum sharing with ARQ-based primary systems'. Together they form a unique fingerprint.

Cite this