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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.