Browsing by Author "Ceniklioğlu, Büşra"

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Citation - Scopus: 7
Analysis of Average Bit Error Rate for Ofdm-Im Systems With Hardware Impairments Over Nakagami-M and Weibull Fading Channels
(Institute of Electrical and Electronics Engineers Inc., 2022) Ceniklioğlu, Büşra; Develi, I.; Canbilen, Ayşe Elif; Lafcı, Mustafa
Orthogonal frequency division multiplexing together with index modulation (OFDM-IM) is a brilliant key alternative to the traditional orthogonal frequency division multiplexing (OFDM) schemes for future communication technologies whereby it has high spectral and energy efficiency. However, there are still key issues that need to be adressed to evaluate possible applications in practical systems. Accordingly, we investigate the performance of OFDM-IM systems over Nakagami-m and Weibull fading channels that suffer from transceiver hardware impairments (HWIs) in this paper. Specifically, a maximum likelihood (ML) detector is applied for OFDM-IM-based transmission and the system performance is analyzed under the effect of HWIs considering average bit error rate (ABER) by utilizing computer simulations. The obtained results show that the HWIs have serious destructive effects on the overall system performance. © 2022 IEEE.
Citation - Scopus: 1
Error Analysis of Ofdm-Im Systems for Beyond 5g: the Effect of Iqi at Transceiver
(Wiley, 2024) Ceniklioğlu, Büşra; Develi, İbrahim; Canbilen, Ayşe Elif
It is well known that hardware impairments (HWIs) can worthy reduce the wireless system performance at high carrier frequencies by showing random effects. Most current researches for 5 GB systems assume that transmitters and receivers (transceivers) are perfectly equipped. But wireless transceivers (TxRx$$ {T}_x{R}_x $$) are affected by HWIs in practice. Considering the previous studies in the literature, it is reported that HWIs have devastating effects on the performance of OFDM and OFDM-index modulation (IM) systems with fading channels. In this paper, in-phase and quadrature phase imbalance (IQI), which is the one of most HWIs between transmitter and receiver in wireless communication systems, is examined on OFDM-IM system over Rayleigh and Nakagami-m$$ m $$ fading channels. Two well-known detectors, the maximum likelihood (ML) detector and the log-likelihood ratio (LLR) detector are used under the effect of the IQI at TxRx$$ {T}_x{R}_x $$. Error performance analyzes over fading channels of the IQI effect on OFDM-IM system are realized first theoretically and then by computer simulations. Results obtained for the presence of IQI at TxRx$$ {T}_x{R}_x $$ show that a performance evaluation based only on the presence of IQI in the receiver would be optimistic and misleading in terms of the performance of real-life OFDM-IM systems. Most current researches for 5 GB systems assume that transmitters and receivers (transceivers) are perfectly equipped. In this paper, in-phase and quadrature phase imbalance (IQI), which is the one of most HWIs between transmitter and receiver in wireless communication systems, is examined on OFDM-IM system over Rayleigh and Nakagami-m fading channels. Results obtained for the presence of IQI at transceiver show that a performance evaluation based only on the presence of IQI in the receiver would be optimistic and misleading in terms of the performance of real-life OFDM-IM systems. image
Citation - WoS: 16
Citation - Scopus: 19
Error Analysis of the Joint Localization and Synchronization of Ris-Assisted Mm-Wave Miso-Ofdm Under the Effect of Hardware Impairments
(IEEE-Inst Electrical Electronics Engineers Inc, 2022) Ceniklioğlu, Büşra; Tubail, Deeb Assad; Canbilen, Ayse Elif; Develi, İbrahim; İkki, Salama S.
This work investigates the theoretical bounds of the joint localization and synchronization processes in a reconfigurable intelligent surface (RIS)-assisted system. We address the case of millimeter-wave ( $mm$ -Wave) multiple-input single-output (MISO) orthogonal frequency-division multiplexing (OFDM) with non-ideal transceivers. Considering a single antenna mobile station (MS) aims to estimate the parameters of the downlinks from the base station (BS) and the RIS by observing a known sequence received by the MS directly from the BS and indirectly through the RIS. The theoretical bounds of the estimation process are assessed by using the Fisher information matrix (FIM). A transformation matrix is then used to convert the FIM of the downlink channel parameters to the FIM of the MS joint localization and synchronization parameters. Specifically, the transformation matrix is derived based on the geometric relationships that convert the estimated downlink channels' parameters to the position coordinates and clock offset. Next, the Cramer-Rao lower bound (CRLB) matrix of the joint localization and synchronization process is obtained by using the pseudo-inverse of the FIM. Thus, the position error bound (PEB), as well as the synchronization error bound (SEB), are calculated. Computer simulation results are provided to illustrate the adverse effects of the hardware impairments (HWIs) on the accuracy of localization and synchronization. These results are given in proportion to the effective signal-to-noise ratio (SNR), the number of pilot transmissions, and the number of the RIS elements.