Yazar "Develi, Ibrahim" seçeneğine göre listele

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    BER Analysis of SM-MIMO Systems with MRC Detectors over Weibull Fading Channels
    (IEEE, 2017) Canbilen, Ayse Elif; Gultekin, Seyfettin Sinan; Develi, Ibrahim
    In this study, hit error rate (BER) performances of 2x4 and 2x8 spatial modulation multiple input multiple output (SM-MIMO) systems over Weibull fading channels are investigated. Transmitted data and the transmitter antenna which conveys the data are estimated by using iterative maximum ratio combining algorithm at the receiver side. BER performance is obtained by changing the value of fading parameter and the level of modulation for several scenarios with computer simulations. While reducing the computational complexity of similar SM-MIMO system which uses maximum likelihood for the estimation procedure, it is obtained up to 13 dB better performance.
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    Imperfect CSI and Improper Gaussian Noise Effects on SSK: Optimal Detection and Error Analysis
    (IEEE, 2018) Alsmadi, Malek M.; Canbilen, Ayse E.; Ikki, Salama S.; Basar, Ertugrul; Gultekin, Seyfettin S.; Develi, Ibrahim
    Space shift keying (SSK) has many advantages through its unique transmission manner as compared to other multiple-input multiple-output (MIMO) techniques. Nevertheless, the practicality of SSK in the presence of real-time imperfections such as channel estimation errors and hardware impairments (HWIs) is still an open research problem. On the other hand, the effects of HWIs are assumed as zero-mean circularly-symmetric complex Gaussian random variable (RV) in the literature. However, this model does not reflect the asymmetric characteristics of different HWIs. Therefore, the aim of this paper is to shed light on the joint effect of improper Gaussian noise (IGN) and imperfect channel state information (ICSI) on the performance of SSK receiver. Particularly, an optimal maximum likelihood (ML) detector is designed, and pairwise error probability (PEP) expression is derived. Additionally, an exact closed-form Cramer-Rao bound expression is calculated for evaluating the channel estimation accuracy under the effect of IGN. The results obtained by using computer simulations prove that the proposed optimal detector is superior to the traditional ML detector in the presence of IGN and ICSI.
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    Spatial Modulation in the Presence of I/Q Imbalance: Optimal Detector & Performance Analysis
    (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2018) Canbilen, Ayse E.; Alsmadi, Malek M.; Basar, Ertugrul; Ikki, Salama S.; Gultekin, Seyfettin S.; Develi, Ibrahim
    Spatial modulation (SM) is affected by the impacts of in-phase and quadrature-phase imbalance (IQI), which cause degradation of system performance in practical terms. To address this concern, an optimal maximum likelihood detector is proposed for SM-based transmission and the system performance is analyzed by computer simulations and analytical derivations. In addition, this optimal receiver is compared with a non-optimal receiver. Specifically, pairwise and average hit error probabilities are derived for the optimal detector. The results prove that IQI is a critical issue for SM-based transmission and the proposed optimal receiver significantly enhances the SM system performance in the presence of IQI.