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Author: search.filters.author.Mi, Si Sar

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    Efficient reduction of peak-to-average power ratio in multiple-input multiple-output orthogonal frequency-division multiplexing system by shuffling cluster sequences
    (2024-12-01)
    Mi, Si Sar
    ;
    Mata, Tanairat
    ;
    Boonsrimuang, Pornpawit
    ;
    Boonsrimuang, Pisit
    We propose a shuffling cluster sequence technique without separate side information (SI) for multiple-input multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM) systems. In the proposed technique, the active subcarriers over two consecutive OFDM symbols are divided into (Formula presented.) clusters, and each cluster (packet frame) includes a header for ID#cluster and payload for (Formula presented.). The (Formula presented.) clusters are shuffled to reduce the peak-to-average power ratio (PAPR) of the time-domain OFDM signal, which includes the information data and SI signals, with a low computational complexity. At the receiver, the information data can be correctly reconstructed by ID#cluster in the header of each cluster, achieving a smaller bit error rate than the conventional MIMO-OFDM system without PAPR reduction. Moreover, our technique is comparable with the conventional partial transmit sequence technique without the impact of a separate SI signal even when increasing the number of transmitter antennas in a nonlinear multipath fading channel.
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    Performance Evaluation of the M-QAM Enhanced Subcarrier Index Modulation in the Multipath Fading Channel with the Non-Linear Amplifier
    (2023-01-01)
    Mi, Si Sar
    ;
    Siriwanitpong, Aphitchaya
    ;
    Boonsrimuang, Pornpawit
    ;
    Boonsrimuang, Pisit
    One of the specifications of the next-generation mobile communication is to reduce the power consumption to transmit the signal. Enhanced subcarrier index modulation (eSIM-OFDM) is a novel multicarrier modulation scheme. However, the eSIM-OFDM scheme degraded a little frequency utilization than the conventional orthogonal frequency division multiplexing (C-OFDM) scheme at the higher M-QAM modulation techniques. It has a special feature to transmit the signal when compared with the C-OFDM scheme. Its special feature increased the power efficiency and improved the bit error rate (BER) performance than the C-OFDM scheme. In the literature, the BER performance of the eSIM-OFDM scheme is analyzed in the additive white Gaussian noise (AWGN) channel and compared BER performance of the C-OFDM scheme. But in the literature, the BER performance of the eSIM-OFDM scheme and C-OFDM scheme were not evaluated in the multipath fading channel. Because eSIM-OFDM includes a special feature called inactive and active subcarriers. In this paper, we will evaluate the BER performance of higher order modulated eSIM-OFDM signal in the multipath Rician fading channel by using the Zadoff-Chu sequence pilot in the non-linear mobile communication system and will compare the BER performance with the C-OFDM scheme. From the simulation results, we can see that the BER performance of the eSIM-OFDM scheme is much better than the C-OFDM scheme in the multipath Rician fading non-linear channel. In this paper, computer simulation will evaluate the BER performance of the higher order modulated eSIM-OFDM scheme in the multipath Rician fading non-linear channel.
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    Channel Estimation for Enhanced Subcarrier Index Modulation OFDM Using Zadoff-Chu Sequence Pilot in Nonlinear Channel
    (2022-01-01)
    Mi, Si Sar
    ;
    Siriwanitpong, Aphichaya
    ;
    Boonsrimuang, Pornpawit
    ;
    Boonsrimuang, Pisit
    Orthogonal Frequency Division Multiplexing with Index Modulation (OFDM-IM) is a digital modulation scheme that conveys additional information bits by using the index of subcarriers. OFDM with enhanced subcarrier index modulation (OFDM-SIM) has been recently proposed to improve the bit error rate (BER) performance of multicarrier communication systems. It is challenging to estimate channel variation of the OFDM-SIM system in wireless communication systems for coherent detection at the receiver side. This paper proposes a new pilot data information Zadoff-Chu sequence for the channel estimation OFDM-SIM system. And OFDM-SIM channel estimation will be done by using the conventional OFDM-SIM symbol pilot and the proposed Zadoff-Chu sequence pilot in the multipath Rician fading channel. And evaluate the simulation results by using BER performance. BER results of channel estimation OFDM-SIM with proposed Zadoff-Chu sequence pilot decreased than BER results of channel estimation OFDM-SIM using conventional OFDM-SIM symbol pilot. And we evaluate the proposed Zadoff-Chu sequence channel estimation OFDM-SIM in a nonlinear multipath Rician fading channel. We can see that the proposed Zadoff-Chu sequence pilot outperformed than conventional OFDM-SIM symbol pilot in every input back off (IBO)=0 dB,-2dB,-4dB, and-6dB. Our proposed channel estimation method is evaluated by using computer simulation.