تصفح حسب المؤلف "�zdemir, �zg�r"
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A regularization approach to MSE analysis of OFDM under phase noise
Kakşi, Ömer; Özdemir, Özgür; Hamila, Ridha; Al-Dhahir, Naofal ( Elsevier , 2018 , Article)Orthogonal frequency division multiplexing (OFDM) is widely used in broadband wireless communications systems because of its high resilience to frequency-selective fading and its low implementation complexity. Phase noise ... -
A threshold-based opportunistic MAC protocol for MIMO wireless sensor networks
Soy, Hakki; Özdemir, Özgür; Bayrak, Mehmet; Hamila, Ridha; Al-Dhahir, Naofal ( IEEE , 2012 , Conference Paper)In this paper, we consider a single-hop wireless sensor network where both the sensor nodes and the controller node have multiple antennas. We focus on single beam opportunistic communication and propose a threshold-based ... -
A USRP-based experimental testbed for OFDM systems impaired by I/Q imbalance
Özdemir, Özgür; Hamila, Ridha; Al-Dhahir, Naofal ( IEEE , 2013 , Conference Paper)In this paper, an experimental testbed for packet based OFDM systems is proposed using USRP RF front-ends. I/Q imbalance estimation and compensation algorithms are implemented at the receiver by manually injecting I/Q ... -
Decentralized multiuser diversity with opportunistic packet transmission in MIMO wireless sensor networks
Soy, Hakki; Özdemir, Özgür; Bayrak, Mehmet; Hamila, Ridha; Al-Dhahir, Naofal ( Elsevier , 2013 , Article)In this study, we consider a single-hop wireless sensor network where both the sensor nodes and the controller node have multiple antennas. We focus on single beam opportunistic communication and propose a threshold-based ... -
Digital baseband compensation of frequency-dependent joint TX/RX I/Q imbalance in beamforming MIMO OFDM transceivers
Özdemir, Özgür; Hamila, Ridha; Al-Dhahir, Naofal ( IEEE , 2012 , Conference Paper)In this paper, we investigate the effects of asymmetric frequency-dependent joint transmit-receive I/Q imbalance on the performance of beamforming MIMO-OFDM systems. We derive the throughput-maximizing transmit/receive ... -
I/Q imbalance in multiple beamforming {OFDM} transceivers: SINR analysis and digital baseband compensation
Özdemir, Özgür; Hamila, Ridha; Al-Dhahir, Naofal ( IEEE , 2013 , Article)In this paper, we start by investigating the impact of joint transmit-receive I/Q imbalance on the performance of direct-conversion beamforming OFDM transceivers. We derive a new analytical expression for the average ... -
Modelling and compensation of frequency-dependent I/Q imbalance in multiple beamforming OFDM transceivers
Özdemir, Özgür; Hamila, Ridha; Al-Dhahir, Naofal ( IEEE , 2012 , Conference Paper)In this paper, we investigate the effects of asymmetric frequency-dependent joint transmit-receive I/Q imbalance on the performance of multiple beamforming MIMO OFDM systems. We derive the throughput-maximizing TX/RX ... -
SINR analysis for beamforming OFDM systems under joint transmit-receive I/Q imbalance
Özdemir, Özgür; Hamila, Ridha; Al-Dhahir, Naofal ( IEEE , 2012 , Conference Paper)In this paper, we derive an analytical expression for the subcarrier average SINR of a beamforming OFDM system in the presence of joint transmit-receive I/Q imbalance. The derived expression quantifies the impact of the ...