Ali Özen

Bildiri | 2019 | IEEE 42th International Conference on Telecommunications and Signal Processing, TSP 2019 , pp.660 - 663

In this paper, a new waveform design based on Lifting Wavelet Transform (LWT) is proposed for next generation wireless communication systems. The proposed waveform design (LWT-UFMC) consists of combination of the LWT and universal filtered multi carrier (UFMC) waveform. It is aimed to improve the performance of the UFMC waveform, which is from the 5th Generation (5G) waveform candidates, with the proposed LWT-UFMC waveform. Computer simulation studies are performed to test the achievement of the recommended waveform and to compare with the classical OFDM and UFMC in AWGN and flat Rayleigh fading channels. It is seen that the propose . . .d waveform from the obtained simulation results has the best and highly satisfactory performance. Daha fazlası Daha az

Ali Özen

Bildiri | 2019 | IEEE 42th International Conference on Telecommunications and Signal Processing, TSP 2019 , pp.651 - 654

In this paper, DT-CWT-OFDM waveform based on dual tree complex wavelet conversion (DT-CWT) is introduced to enhance the achievement of the classical OFDM waveform. IFFT/FFT blocks used in the classical OFDM waveform are replaced with IDTCWT/DTCWT blocks in the DT-CWT-OFDM waveform. In order to confirm the achievement of the investigated waveform and compare it with the waveforms of classical OFDM and discrete wavelet conversion based OFDM (DWT-OFDM), computer simulation studies are carried out on AWGN, flat Rayleigh damping and frequency-selective Rayleigh damping channels. It is seen from the attained simulation outcomes that the D . . .T-CWT-OFDM waveform has better achievement than the classical OFDM and DWT-OFDM waveforms and also provides approximately 6 dB SNR gain against the classical OFDM and approximately 1.5 dB SNR gain against the DWT-OFDM for a BER value of 1E-4 Daha fazlası Daha az

Ali ÖZEN

Bildiri | 2019 | 3. International Scientific and Vocational Studies Congress , pp.1 - 6

In this study, zero tail inverse Lifting wavelet transform spread fast Walsh Hadamard transformed OFDM (ZT-ILWTs FWHT OFDM) is recommended as an alternative to the OFDM waveform for the new generation of wireless transmission systems. The recommended waveform is composed of a combination of inverse Lifting wavelet transform (ILWT) and fast Walsh Hadamard transform (FWHT) with OFDM waveform. The proposed waveform is tested with computer simulation studies for bit error rate (BER), peak to average power ratio (PAPR) and out of band emission (OOBE) performance criteria. From the attained results, it is observed that the recommended wav . . .eform is better than classical OFDM and zero-tail discrete Fourier transform spread OFDM (ZT-DFT-S OFDM) waveforms for all three performance criteria Daha fazlası Daha az

Ali ÖZEN

Bildiri | 2018 | IEEE 41th International Conference on Telecommunications and Signal Processing, TSP 2018 , pp.9 - 12

In this paper, zero-tail discrete cosine transform spread OFDM (ZT DCT-S OFDM) waveform is proposed as an alternative to 5th generation (5G) waveform enhancement studies. In order to verify the performance of the proposed method and compare with the conventional OFDM and zero-tail discrete Fourier transform spread OFDM (ZT DFT-S OFDM) systems, computer simulations are performed on time invariant and time variant frequency selective Rayleigh fading channels. The obtained simulation results show that the proposed ZT DCTS OFDM method has better bit error rate (BER) and channel tracking (carrier frequency offset, CFO) performance than c . . .onventional OFDM and ZT DFT-S OFDM systems Daha fazlası Daha az

Ali ÖZEN | Büşra CENİKLİOĞLU

Bildiri | 2018 | IEEE 41th International Conference on Telecommunications and Signal Processing, TSP 2018 , pp.13 - 16

In this study, a novel zero tail discrete wavelet transform spread orthogonal wavelet division multiplexing (ZT DWT-S OWDM) waveform design has been proposed as a solution to the problem of poor peak to average power ratio (PAPR) performance of conventional orthogonal frequency division multiplexing (OFDM) systems. The effects of different waveletfamilies such as Haar, Daubechies, Symlets, Coiflets and Bi-Orthogonal on PAPR performance of ZT DWT-S OWDM systems are investigated. Computer simulation studies are carried out to compare the ZT DWT-S OWDM waveform with the conventional OFDM and zero-tail discrete Fourier transform spread . . .OFDM (ZT DFT-S OFDM) waveforms. The results show that the ZT DWT-S OWDM waveform has better PAPR performance than the conventional OFDM and ZT DFT-S OFDM waveforms. In particular, it is observed that ZT DWT-S OWDM using Bi-Orthogonal wavelet family has the best PAPR performance. Daha fazlası Daha az

Ali ÖZEN

Bildiri | 2017 | IEEE 40th International Conference on Telecommunications and Signal Processing, TSP 2017 , pp.195 - 199

A novel hybrid orthogonal frequency division multiplexing (H-OFDM) technique, for 5G candidate waveforms, has been proposed to improve the performance of conventional OFDM systems in this paper. In H-OFDM system instead of conventional cyclic prefixes (CPs) it is used hybrid CP as a guard interval. The hybrid CP consists of zero tail (ZT), unique word (UW) and CP. Computer simulations have been performed to show the performance of the proposed system in stationary and non-stationary frequency selective Rayleigh fading channels. The obtained simulation results using IEEE 802.16 physical layer specifications have demonstrated that the . . . proposed H-OFDM method has considerably better performance and Doppler shift tracking than conventional OFDM. Daha fazlası Daha az

Ali ÖZEN

Bildiri | 2020 | 43rd International Conference on Telecommunications and Signal Processing (TSP) , pp.195 - 199

In this study, zero tail inverse Lifting wavelet transform spread fast Walsh Hadamard transformed OFDM (ZT-ILWTs FWHT OFDM) is recommended as an alternative to the OFDM waveform for the new generation of wireless transmission systems. The recommended waveform is composed of a combination of inverse Lifting wavelet transform (ILWT) and fast Walsh Hadamard transform (FWHT) with OFDM waveform. The proposed waveform is tested with computer simulation studies for bit error rate (BER), peak to average power ratio (PAPR) and out of band emission (OOBE) performance criteria. From the attained results, it is observed that the recommended wav . . .eform is better than classical OFDM and zero-tail discrete Fourier transform spread OFDM (ZT-DFT-S OFDM) waveforms for all three performance criteria Daha fazlası Daha az

Ali ÖZEN | Asuman SAVAŞÇIHABEŞ

Makale/Derleme | 2020 | IEEJ Transactions on Electrical and Electronic Engineering

A novel concatenated Lifting Wavelet Transform (LWT) and Walsh Hadamard Transform (WHT) with Universal Filtered MultiCarrier (UFMC) waveform is suggested as an alternative to Orthogonal Frequency Division Multiplexing (OFDM) waveformfor the next generation wireless telecommunication systems in this paper. The suggested waveform is composed of LWT andWHT with UFMC waveform. Both the elimination the disadvantages of OFDM and the improvement the achievement of UFMCwaveform, from the fifth generation waveform candidates, has been aimed with the suggested waveform. In order to verify theperformance of the suggested waveform and compare w . . .ith the traditional OFDM, UFMC, and LWT-UFMC waveform computersimulation studies are performed in additive white Gaussian noise and flat Rayleigh fading channel environments. The acquiredcomputer simulation results exhibit that the achievement of the suggested waveform has better than the achievement of thetraditional OFDM, UFMC, and LWT-UFMC waveform.©2021 Institute of Electrical Engineers of Japan. Published by WileyPeriodicals LLC Daha fazlası Daha az

Asuman SAVAŞÇIHABEŞ | Ali ÖZEN

Makale/Derleme | 2021 | Sensors

In this paper, a new WHT-LWT-GFDM waveform obtained by combining Walsh–Hadamard Transform (WHT), Lifting Wavelet Transform (LWT), and Generalized Frequency Division Multiplexing (GFDM) is presented for use in next-generation wireless communication systems. The proposed approach meets the requirement of 5th-generation (5G) and beyond communication schemes in terms of low latency, low peak-to-average-power ratio (PAPR), and low bit-error rate (BER). To verify the performance of the presented waveform, PAPR and BER simulation results were obtained in additive white Gaussian noise (AWGN) and flat Rayleigh fading channels, and the perfor . . .mance of the proposed system was compared with conventional Orthogonal Frequency Division Multiplexing (OFDM), GFDM, and Walsh–Hadamard transform-based GFDM (WHT-GFDM). Simulation results show that the proposed waveform achieves the best BER and PAPR performances and it provides considerable performance gains over the conventional waveforms Daha fazlası Daha az

Ali ÖZEN | Asuman SAVAŞÇIHABEŞ

Bildiri | 2021 | IEEE 44th International Conference On Telecommunications And Signal Processing, Tsp 2021 , pp.394 - 398

In this paper, it is recommended to combine the partial transmit sequence (PTS) and amplitude clipping (AC) methods as a solution to the peak to average power ratio (PAPR) problem of multi-carrier (MC) communication systems. The suggested technique is verified on zero tail discrete cosine transform spread OFDM (ZT-DCT-s OFDM), ZT discrete Fourier transform spread OFDM (ZT-DFT-s OFDM) and ZT discrete sine transform spread OFDM (ZT-DST-s OFDM) waveforms, from the next generation waveform alternative to OFDM, with classical OFDM waveform. Computer simulation studies are performed to verify the success of the recommended PTS-AC method o . . .ver bit error rate (BER) and PAPR achievement benchmark. From the obtained results, it is observed that the suggested technique provides approximately 6 dB PAPR enhancement versus the original versions of the waveforms without compromising the BER performance. Daha fazlası Daha az