Öztürk, Ertan | Özer, Mahmut
Proceedings | 2005 | Proceedings of the IEEE 13th Signal Processing and Communications Applications Conference, SIU 20052005 , pp.147 - 150
Voltage-gated ion channels in neuronal membrane show random fluctuations between different conformational states. These fluctuations give rise to channel noise current. This channel noise current is of great importance in the determination single-channel properties of voltage-gated ion channels. In this study, single-channel currents of potassium and sodium channels in Wang-Buzsaki neuronal model are examined, and their single-channel conductances and total sodium and potassium channel numbers in the membrane are computed by using non-stationary noise analysis. © 2005 IEEE.
Öztürk, Ertan | Yılmaz, Ergin
Article | 2009 | Telecommunication Systems42 ( 03.Apr ) , pp.213 - 222
In this paper, we first investigate the power spectral densities (PSD) of bipolar modulated Direct Sequence Ultra Wide Band (DS-UWB) signals using various pulse shapes under the FCC UWB emission mask. Considered pulse shapes are the first five derivatives of the Gauss pulse (p 1 , p 2 , p 3 , p 4 and p 5 ), the first four orthogonal modified Hermite waveforms, and Daubechies wavelets (db-q). It is observed in the PSD results that p 4 and p 5 Gauss pulses, the Daubechies (db-q) for q>4 comply with the FCC UWB rule by selecting proper values for the pulse duration. Then, we derive the pulse shape dependent probability of error expr . . .ession for bipolar DS-UWB signals over the standard UWB channel. The five pulse shapes (p 4 , p 5 , db-5, db-6 and db-7) complying with the FCC emission mask are numerically compared by using the derived probability of error expression over the CM1 model of the Standard UWB channel. Results reveal that the Daubechies have better performance than those of the two Gauss pulses. © 2009 Springer Science+Business Media, LLC Daha fazlası Daha az
Öztürk, Ertan | Yılmaz, Ergin
Proceedings | 2007 | MobiWac'07 - Proceedings of the 5th ACM International Workshop on Mobility Management and Wireless Access , pp.107 - 111
In this paper, we investigate the probability of error performance of Direct Sequence Ultra Wide Band (DS-UWB) signals using various pulse shapes over the CM1 model of the Standard UWB channel. The considered pulse shapes are the first and second derivatives of Gauss waveform, Rayleigh waveform, and first four orthogonal modified Hermite waveforms. Results reveals that the probability of errors for all available pulse shapes over the considered channel are very similar for few users. However, by increasing the number of users, the performance differences start to appear in favor of Hermite pulses. © 2007 ACM.
Öztürk, Ertan | Yılmaz, Ergin
Proceedings | 2007 | 2007 IEEE 15th Signal Processing and Communications Applications, SIU , pp.107 - 111
In this paper, the probabilities of error performances of bipolar Direct Sequence Ultra Wide Band (DS-UWB) signals are investigated over a log-normal fading channel. Since the bandwidth of UWB signals is in the level of giga Hertz, the number of the resolvable paths in the channel is large. Consequently, in the receiver, a Rake receiver in conjunction with a maximum ratio combiner is used. By using the derived probability of error expression, the numerical values of the performances are calculated for the first derivative of Gaussian, the second derivative of Gaussian, Rayleigh and Daubechies-5 (db-5) pulse signals. Results show tha . . .t the db-5 pulse based UWB system gives the best performance Daha fazlası Daha az
Emir, Ahmet | Kaya, Hakan | Öztürk, Ertan
Proceedings | 2015 | 2015 23RD SIGNAL PROCESSING AND COMMUNICATIONS APPLICATIONS CONFERENCE (SIU) , pp.300 - 303
In this work, Orthogonal Frequency Division Multiplexing (OFDM) is implemented on TMS320C6713 Digital Signal Processors (DSP) Starter Kit (DSK). Transmitter, receiver and communication channel are all implemented on a same kit. Firstly the design is tested within Matlab Simulink environment, and then by configuring C6713 DSK parameters, Simulink blocks relating to C6713 DSK are added into the design. The machine codes generated by compiling the design are loaded to the DSP kit. By comparing the voice signals generated via the simulation and the card, the obtained results are validated.
Kara, Ferdi | Kaya, Hakan | Erkaymaz, Okan | Öztürk, Ertan
Proceedings | 2016 | Proceedings of the 2016 International Symposium on INnovations in Intelligent SysTems and Applications, INISTA 2016 , pp.300 - 303
In wireless communications, the cooperative communication (CC) technology promises performance gains compared to traditional Single-Input Single Output (SISO) techniques. Therefore, the CC technique is one of the nominees for 5G networks. In the Decode-And-Forward (DF) relaying scheme which is one of the CC techniques, determination of the threshold value at the relay has a key role for the system performance and power usage. In this paper, we propose prediction of the optimal threshold values for the best relay selection scheme in cooperative communications, based on Artificial Neural Networks (ANNs) for the first time in literatur . . .e. The average link qualities and number of relays have been used as inputs in the prediction of optimal threshold values using Artificial Neural Networks (ANNs): Multi-Layer Perceptron (MLP) and Radial Basis Function (RBF) networks. The MLP network has better performance from the RBF network on the prediction of optimal threshold value when the same number of neurons is used at the hidden layer for both networks. Besides, the optimal threshold values obtained using ANNs are verified by the optimal threshold values obtained numerically using the closed form expression derived for the system. The results show that the optimal threshold values obtained by ANNs on the best relay selection scheme provide a minimum Bit-Error-Rate (BER) because of the reduction of the probability that error propagation may occur. Also, for the same BER performance goal, prediction of optimal threshold values provides 2dB less power usage, which is great gain in terms of green communication. © 2016 IEEE Daha fazlası Daha az