Yazar "Tavallali, Pooya" seçeneğine göre listele

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    Bit and Packet Error Rate evaluations for Half-Cycle stage cooperation on 6G wireless networks
    (ELSEVIER, RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS, 2021) Attar, Hani H.; Solyman, Ahmad Amin Ahmad; Khosravi, Mohammad R.; Qi, Lianyong; Alhihi, Mohammad; Tavallali, Pooya
    The excellent features of the sixth generation (6G) of wireless technology enthuses researchers to apply advanced and complex techniques on mobile communication networks, which is what this paper explores. As a result of the ability of 6G to exchange vast data rates and network programming, the Cooperative Network Coding (CoNC) technique can be implemented to improve the connectivity and diversity within 6G applications. Though CoNC is usually implemented at the second stage, this paper proposes dividing the first stage into two Half-Cycle stages, and then applying CoNC at the second Half-Cycle stage. The resulting Bit Error Rate (BER) behaviour is investigated on the physical layer for direct data exchange in 6G local mobile networks over an Additive White Gaussian Noise (AWGN) channel. Partial Unit Turbo Code (PUTC) (4,2,1,4) and (8,4,3,8) are used by each mobile node as the forward error correction technique, which means that each mobile acts as a Base Station (BS) for other mobiles in the local network by applying CoNC on the received packets, and then each mobile node (or BS), either Amplify-and-Forward (AF), or Decode-re-encode-amplify and Forward (DF), acts. When full connectivity is not achieved at the end of the first two Half-Cycle stages, new Half-Cycle stage transmissions follow, and the BER behaviour for all additional Half-Cycle stages is obtained. The results illustrate that applying CoNC at the second Half-Cycle stage of the first general stage produces a limited BER loss. To mitigate the damage in the BER, a soft-decision PUMTC decoder is also proposed.
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    Efficient equalisers for OFDM and DFrFT-OCDM multicarrier systems in mobile E-health video broadcasting with machine learning perspectives
    (ELSEVIER, RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS, 2020) Attar, Hani H.; Solyman, Ahmad Amin Ahmad; Mohamed, Abd-Elnaser Fawzy; Khosravi, Mohammad R.; Menon, Varun G.; Bashir, Ali Kashif; Tavallali, Pooya
    Recently, the orthogonal frequency-division multiplexing (OFDM) system has become an appropriate technique to be applied on the physical layer in various requests, mainly in wireless communication standards, which is the reason to use OFDM within mobile wireless medical applications. The OFDM with cyclic prefix (CP) can compensate lacks for the time-invariant multi-path channel effects using a single tap equaliser. However, for mobile wireless communication, such as the use of OFDM in ambulances, the Doppler shift is expected, which produces a doubly dispersive communication channel where a complex equaliser is needed. This paper proposes a low-complexity band LDLH factorisation equaliser to be applied in mobile medical communication systems. Moreover, the discrete fractional Fourier transform (DFrFT) is used to improve the communication system’s performance over the OFDM. The proposed low-complexity equaliser could improve the OFDM, and the DFrFT-orthogonal chirpdivision multiplexing (DFrFT-OCDM) system’s performance, as illustrated in the simulation results. This proves that the recommended system outperforms the standard benchmark system, which is an essential factor as it is to be applied within mobile medical systems.
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    A Low-Complexity Equalizer for Video Broadcasting in Cyber-Physical Social Systems Through Handheld Mobile Devices
    (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA, 2020) Solyman, Ahmad Amin Ahmad; Attar, Hani; Khosravi, Mohammad R.; Menon, Varun G.; Jolfaei, Alireza; Balasubramanian, Venki; Selvaraj, Buvana; Tavallali, Pooya
    In Digital Video Broadcasting-Handheld (DVB-H) devices for cyber-physical social systems, the Discrete Fractional Fourier Transform-Orthogonal Chirp Division Multiplexing (DFrFT-OCDM) has been suggested to enhance the performance over Orthogonal Frequency Division Multiplexing (OFDM) systems under time and frequency-selective fading channels. In this case, the need for equalizers like the Minimum Mean Square Error (MMSE) and Zero-Forcing (ZF) arises, though it is excessively complex due to the need for a matrix inversion, especially for DVB-H extensive symbol lengths. In this work, a low complexity equalizer, Least-Squares Minimal Residual (LSMR) algorithm, is used to solve the matrix inversion iteratively. The paper proposes the LSMR algorithm for linear and nonlinear equalizers with the simulation results, which indicate that the proposed equalizer has significant performance and reduced complexity over the classical MMSE equalizer and other low complexity equalizers, in time and frequency-selective fading channels.