Distributed Beamforming for Two-Way DF Relay Cognitive Networks under Primary-Secondary Mutual Interference

Ali Afana, Ali Ghrayeb, Vahid Reza Asghari, Sofiene Affes

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

In this paper, we consider collaborative beamforming for a cooperative two-way relay spectrum-sharing system where a pair of secondary transceivers communicates via a set of secondary decode-and-forward (DF) relays in the presence of multiple primary transceivers. Among the available relays, only those that receive the signals reliably participate in the cooperative beamforming process and use network coding to simultaneously transmit the weighted signals to the transceivers. Two practical two-way relaying strategies are investigated, namely, DF- xoring and DF-superposition. The former is based on bitwise-level xoring of the detected signals at the relays, whereas the latter is based on symbolwise-level addition at the relays. For each relaying strategy, we derive general optimal beamforming vectors at the relays to keep the interference inflicted on the primary receivers to a predefined threshold. Employing zero-forcing beamforming as a special case, we present an analytical framework of the performance of the secondary system considering the effect of the primary-secondary mutual cochannel interference (CCI). In particular, we derive closed-form expressions for the outage probability, bit error rate (BER), and achievable sum rates over independent and identically distributed Rayleigh fading channels. Numerical results demonstrate the effectiveness of beamforming in compensating for the cognitive system performance loss due to CCI in addition to mitigating the interference to the primary receivers. Simulation results also show that, when the received signals at the relays are equally weighted, DF- xor always outperforms both DF-superposition and amplify-and-forward (AF) relaying.

Original languageEnglish
Article number6920068
Pages (from-to)3918-3930
Number of pages13
JournalIEEE Transactions on Vehicular Technology
Volume64
Issue number9
DOIs
Publication statusPublished - 1 Sep 2015

Fingerprint

Decode-and-forward
Beamforming
Relay
Interference
Transceivers
Cochannel interference
Telecommunication repeaters
Co-channel Interference
Cognitive systems
Superposition
Network coding
Receiver
Rayleigh fading
Outages
Fading channels
Bit error rate
Cognitive Systems
Spectrum Sharing
Zero-forcing
Rayleigh Fading Channel

Keywords

  • Cognitive radio
  • distributed beamforming
  • performance analysis
  • spectrum sharing systems
  • two-way relaying

ASJC Scopus subject areas

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

Cite this

Distributed Beamforming for Two-Way DF Relay Cognitive Networks under Primary-Secondary Mutual Interference. / Afana, Ali; Ghrayeb, Ali; Asghari, Vahid Reza; Affes, Sofiene.

In: IEEE Transactions on Vehicular Technology, Vol. 64, No. 9, 6920068, 01.09.2015, p. 3918-3930.

Research output: Contribution to journalArticle

@article{32ad59adc95b456cae6d59afa9e3e355,
title = "Distributed Beamforming for Two-Way DF Relay Cognitive Networks under Primary-Secondary Mutual Interference",
abstract = "In this paper, we consider collaborative beamforming for a cooperative two-way relay spectrum-sharing system where a pair of secondary transceivers communicates via a set of secondary decode-and-forward (DF) relays in the presence of multiple primary transceivers. Among the available relays, only those that receive the signals reliably participate in the cooperative beamforming process and use network coding to simultaneously transmit the weighted signals to the transceivers. Two practical two-way relaying strategies are investigated, namely, DF- xoring and DF-superposition. The former is based on bitwise-level xoring of the detected signals at the relays, whereas the latter is based on symbolwise-level addition at the relays. For each relaying strategy, we derive general optimal beamforming vectors at the relays to keep the interference inflicted on the primary receivers to a predefined threshold. Employing zero-forcing beamforming as a special case, we present an analytical framework of the performance of the secondary system considering the effect of the primary-secondary mutual cochannel interference (CCI). In particular, we derive closed-form expressions for the outage probability, bit error rate (BER), and achievable sum rates over independent and identically distributed Rayleigh fading channels. Numerical results demonstrate the effectiveness of beamforming in compensating for the cognitive system performance loss due to CCI in addition to mitigating the interference to the primary receivers. Simulation results also show that, when the received signals at the relays are equally weighted, DF- xor always outperforms both DF-superposition and amplify-and-forward (AF) relaying.",
keywords = "Cognitive radio, distributed beamforming, performance analysis, spectrum sharing systems, two-way relaying",
author = "Ali Afana and Ali Ghrayeb and Asghari, {Vahid Reza} and Sofiene Affes",
year = "2015",
month = "9",
day = "1",
doi = "10.1109/TVT.2014.2362571",
language = "English",
volume = "64",
pages = "3918--3930",
journal = "IEEE Transactions on Vehicular Technology",
issn = "0018-9545",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "9",

}

TY - JOUR

T1 - Distributed Beamforming for Two-Way DF Relay Cognitive Networks under Primary-Secondary Mutual Interference

AU - Afana, Ali

AU - Ghrayeb, Ali

AU - Asghari, Vahid Reza

AU - Affes, Sofiene

PY - 2015/9/1

Y1 - 2015/9/1

N2 - In this paper, we consider collaborative beamforming for a cooperative two-way relay spectrum-sharing system where a pair of secondary transceivers communicates via a set of secondary decode-and-forward (DF) relays in the presence of multiple primary transceivers. Among the available relays, only those that receive the signals reliably participate in the cooperative beamforming process and use network coding to simultaneously transmit the weighted signals to the transceivers. Two practical two-way relaying strategies are investigated, namely, DF- xoring and DF-superposition. The former is based on bitwise-level xoring of the detected signals at the relays, whereas the latter is based on symbolwise-level addition at the relays. For each relaying strategy, we derive general optimal beamforming vectors at the relays to keep the interference inflicted on the primary receivers to a predefined threshold. Employing zero-forcing beamforming as a special case, we present an analytical framework of the performance of the secondary system considering the effect of the primary-secondary mutual cochannel interference (CCI). In particular, we derive closed-form expressions for the outage probability, bit error rate (BER), and achievable sum rates over independent and identically distributed Rayleigh fading channels. Numerical results demonstrate the effectiveness of beamforming in compensating for the cognitive system performance loss due to CCI in addition to mitigating the interference to the primary receivers. Simulation results also show that, when the received signals at the relays are equally weighted, DF- xor always outperforms both DF-superposition and amplify-and-forward (AF) relaying.

AB - In this paper, we consider collaborative beamforming for a cooperative two-way relay spectrum-sharing system where a pair of secondary transceivers communicates via a set of secondary decode-and-forward (DF) relays in the presence of multiple primary transceivers. Among the available relays, only those that receive the signals reliably participate in the cooperative beamforming process and use network coding to simultaneously transmit the weighted signals to the transceivers. Two practical two-way relaying strategies are investigated, namely, DF- xoring and DF-superposition. The former is based on bitwise-level xoring of the detected signals at the relays, whereas the latter is based on symbolwise-level addition at the relays. For each relaying strategy, we derive general optimal beamforming vectors at the relays to keep the interference inflicted on the primary receivers to a predefined threshold. Employing zero-forcing beamforming as a special case, we present an analytical framework of the performance of the secondary system considering the effect of the primary-secondary mutual cochannel interference (CCI). In particular, we derive closed-form expressions for the outage probability, bit error rate (BER), and achievable sum rates over independent and identically distributed Rayleigh fading channels. Numerical results demonstrate the effectiveness of beamforming in compensating for the cognitive system performance loss due to CCI in addition to mitigating the interference to the primary receivers. Simulation results also show that, when the received signals at the relays are equally weighted, DF- xor always outperforms both DF-superposition and amplify-and-forward (AF) relaying.

KW - Cognitive radio

KW - distributed beamforming

KW - performance analysis

KW - spectrum sharing systems

KW - two-way relaying

UR - http://www.scopus.com/inward/record.url?scp=84942155102&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84942155102&partnerID=8YFLogxK

U2 - 10.1109/TVT.2014.2362571

DO - 10.1109/TVT.2014.2362571

M3 - Article

AN - SCOPUS:84942155102

VL - 64

SP - 3918

EP - 3930

JO - IEEE Transactions on Vehicular Technology

JF - IEEE Transactions on Vehicular Technology

SN - 0018-9545

IS - 9

M1 - 6920068

ER -