Opportunistic spectrum sharing in relay-assisted cognitive systems with imperfect CSI

Karama Hamdi, Mazen O. Hasna, Ali Ghrayeb, Khaled Letaief

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

In this paper, we consider spectrum sharing between cognitive radio (CR) users and a licensed primary user (PU) to enhance the spectrum efficiency. In the considered scenario, the PU is not able to successfully transmit data to the intended receiver. In this case, the cognitive base station (CBS) in the vicinity of the primary network offers its help to transmit the primary data. In return, the CR system shares the spectrum with the primary system. In particular, we formulate an opportunistic spectrum sharing approach that determines the optimal beamforming weights at the CBS to maximize the overall worst throughput of the CRs while guaranteeing a certain quality of service (QoS) for the PU. Various formulations of beamforming are proposed, which consider different relaying scenarios, including robust designs that are applicable with imperfect channel state information (CSI) at the PU. The original optimization problems are nonconvex and do not have any closed-form solutions. However, using a convex optimization approach, we transform them into convex forms and find approximate solutions using semidefinite programming (SDP) along with randomization techniques. We consider different examples that demonstrate the efficiency of the proposed approach.

Original languageEnglish
Article number6657777
Pages (from-to)2224-2235
Number of pages12
JournalIEEE Transactions on Vehicular Technology
Volume63
Issue number5
DOIs
Publication statusPublished - 2014

Fingerprint

Cognitive systems
Cognitive Systems
Spectrum Sharing
Channel state information
Channel State Information
Cognitive radio
Beamforming
Imperfect
Base stations
Relay
Convex optimization
Radio systems
Cognitive Radio
Quality of service
Throughput
Scenarios
Robust Design
Semidefinite Programming
Randomisation
Convex Optimization

Keywords

  • Broadcast channels
  • cognitive radio (CR)
  • multiple-input-multiple-output
  • relaying
  • semidefinite programming (SDP) relaxation
  • spectrum sharing

ASJC Scopus subject areas

  • Automotive Engineering
  • Aerospace Engineering
  • Computer Networks and Communications
  • Applied Mathematics
  • Electrical and Electronic Engineering

Cite this

Opportunistic spectrum sharing in relay-assisted cognitive systems with imperfect CSI. / Hamdi, Karama; Hasna, Mazen O.; Ghrayeb, Ali; Letaief, Khaled.

In: IEEE Transactions on Vehicular Technology, Vol. 63, No. 5, 6657777, 2014, p. 2224-2235.

Research output: Contribution to journalArticle

@article{9cacf2a5c048492ea924c82ac413412b,
title = "Opportunistic spectrum sharing in relay-assisted cognitive systems with imperfect CSI",
abstract = "In this paper, we consider spectrum sharing between cognitive radio (CR) users and a licensed primary user (PU) to enhance the spectrum efficiency. In the considered scenario, the PU is not able to successfully transmit data to the intended receiver. In this case, the cognitive base station (CBS) in the vicinity of the primary network offers its help to transmit the primary data. In return, the CR system shares the spectrum with the primary system. In particular, we formulate an opportunistic spectrum sharing approach that determines the optimal beamforming weights at the CBS to maximize the overall worst throughput of the CRs while guaranteeing a certain quality of service (QoS) for the PU. Various formulations of beamforming are proposed, which consider different relaying scenarios, including robust designs that are applicable with imperfect channel state information (CSI) at the PU. The original optimization problems are nonconvex and do not have any closed-form solutions. However, using a convex optimization approach, we transform them into convex forms and find approximate solutions using semidefinite programming (SDP) along with randomization techniques. We consider different examples that demonstrate the efficiency of the proposed approach.",
keywords = "Broadcast channels, cognitive radio (CR), multiple-input-multiple-output, relaying, semidefinite programming (SDP) relaxation, spectrum sharing",
author = "Karama Hamdi and Hasna, {Mazen O.} and Ali Ghrayeb and Khaled Letaief",
year = "2014",
doi = "10.1109/TVT.2013.2289878",
language = "English",
volume = "63",
pages = "2224--2235",
journal = "IEEE Transactions on Vehicular Technology",
issn = "0018-9545",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "5",

}

TY - JOUR

T1 - Opportunistic spectrum sharing in relay-assisted cognitive systems with imperfect CSI

AU - Hamdi, Karama

AU - Hasna, Mazen O.

AU - Ghrayeb, Ali

AU - Letaief, Khaled

PY - 2014

Y1 - 2014

N2 - In this paper, we consider spectrum sharing between cognitive radio (CR) users and a licensed primary user (PU) to enhance the spectrum efficiency. In the considered scenario, the PU is not able to successfully transmit data to the intended receiver. In this case, the cognitive base station (CBS) in the vicinity of the primary network offers its help to transmit the primary data. In return, the CR system shares the spectrum with the primary system. In particular, we formulate an opportunistic spectrum sharing approach that determines the optimal beamforming weights at the CBS to maximize the overall worst throughput of the CRs while guaranteeing a certain quality of service (QoS) for the PU. Various formulations of beamforming are proposed, which consider different relaying scenarios, including robust designs that are applicable with imperfect channel state information (CSI) at the PU. The original optimization problems are nonconvex and do not have any closed-form solutions. However, using a convex optimization approach, we transform them into convex forms and find approximate solutions using semidefinite programming (SDP) along with randomization techniques. We consider different examples that demonstrate the efficiency of the proposed approach.

AB - In this paper, we consider spectrum sharing between cognitive radio (CR) users and a licensed primary user (PU) to enhance the spectrum efficiency. In the considered scenario, the PU is not able to successfully transmit data to the intended receiver. In this case, the cognitive base station (CBS) in the vicinity of the primary network offers its help to transmit the primary data. In return, the CR system shares the spectrum with the primary system. In particular, we formulate an opportunistic spectrum sharing approach that determines the optimal beamforming weights at the CBS to maximize the overall worst throughput of the CRs while guaranteeing a certain quality of service (QoS) for the PU. Various formulations of beamforming are proposed, which consider different relaying scenarios, including robust designs that are applicable with imperfect channel state information (CSI) at the PU. The original optimization problems are nonconvex and do not have any closed-form solutions. However, using a convex optimization approach, we transform them into convex forms and find approximate solutions using semidefinite programming (SDP) along with randomization techniques. We consider different examples that demonstrate the efficiency of the proposed approach.

KW - Broadcast channels

KW - cognitive radio (CR)

KW - multiple-input-multiple-output

KW - relaying

KW - semidefinite programming (SDP) relaxation

KW - spectrum sharing

UR - http://www.scopus.com/inward/record.url?scp=84901631193&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84901631193&partnerID=8YFLogxK

U2 - 10.1109/TVT.2013.2289878

DO - 10.1109/TVT.2013.2289878

M3 - Article

VL - 63

SP - 2224

EP - 2235

JO - IEEE Transactions on Vehicular Technology

JF - IEEE Transactions on Vehicular Technology

SN - 0018-9545

IS - 5

M1 - 6657777

ER -