Uplink achievable rate in underlay random access OFDM-based cognitive radio networks

Han Bae Kong, Sabit Ekin, Erchin Serpedin, Khalid Qaraqe

Research output: Contribution to journalArticle


This paper investigates the uplink achievable rate of secondary users (SUs) in underlay orthogonal frequency division multiplexing based cognitive radio networks, where the SUs randomly access the subcarriers of the primary network. In practice, the primary base stations (PBSs), such as cellular base stations, may not be placed close to each other to mitigate the interferences among them. In this regard, we model the spatial distribution of the PBSs as a β-Ginibre point process which captures the repulsive placement of the PBSs. It is assumed that in order to alleviate the interferences at the PBSs from the SUs, each SU controls its transmit power based on the average interference level at the closest PBS induced by the SU. We first analytically identify the characteristics of the transmit powers at the SUs. Then, tight approximations of the uplink achievable rate of the secondary network are provided in two different scenarios that assume either a decentralized or centralized allocation of the SUs’ subcarriers, respectively. The accuracy of our analytical results is validated by simulation results.

Original languageEnglish
Article number22
JournalEurasip Journal on Wireless Communications and Networking
Issue number1
Publication statusPublished - 1 Dec 2019



  • Cognitive radio
  • Orthogonal frequency division multiplexing
  • Random access
  • Stochastic geometry
  • Underlay network

ASJC Scopus subject areas

  • Signal Processing
  • Computer Science Applications
  • Computer Networks and Communications

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