Open AccessWay to design an orthogonal frequency‐division multiple access‐base station receiver disturbed by a narrowband interfering cognitive radio signal
Author(s) -
Poveda Héctor,
Ferré Guillaume,
Grivel Eric
Publication year - 2015
Publication title -
iet communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.355
H-Index - 62
eISSN - 1751-8636
pISSN - 1751-8628
DOI - 10.1049/iet-com.2014.1122
Subject(s) - narrowband , cognitive radio , multipath propagation , computer science , fading , telecommunications link , orthogonal frequency division multiple access , wideband , base station , transmitter , channel (broadcasting) , signal (programming language) , transmission (telecommunications) , telecommunications , electronic engineering , algorithm , wireless , orthogonal frequency division multiplexing , engineering , programming language
This study deals with an interweave cognitive‐radio (CR) system, where an uplink orthogonal frequency‐division multiple access system is considered for the primary users (PUs). Our purpose is to estimate the PU carrier frequency offsets (PU‐CFOs) as well as the channels to estimate the transmitted symbols. However, in wideband wireless communications, the PU received‐signal spectrum usually exhibits a localised fading because of the multipath propagation channel. When the PU faded frequencies are used by the CR system, the PU system is contaminated by a CR narrowband interference (CR‐NBI). In that case, if a Kalman filter (KF)‐based approach is used for the estimations of the CFOs and the channels, the state‐space representation does not necessarily take into account the CR‐NBI; this hence has a negative impact on the algorithm performance. Therefore the authors propose to make this solution more robust to the CR‐NBI by detecting when it appears and disappears to avoid using the data disturbed by the CR‐NBI. The authors’ contribution is to assume that the CR‐NBI is because of the transmission of contiguous blocks and to propose various criteria based on the covariance matrix of the KF innovation.