To overcome the unbalanced signal-to-noise ratio(SNR)among data-carrying subcarriers(SCs)induced by the imperfect frequency response of optoelectronic devices and various interferences,a channel-independent partial da...To overcome the unbalanced signal-to-noise ratio(SNR)among data-carrying subcarriers(SCs)induced by the imperfect frequency response of optoelectronic devices and various interferences,a channel-independent partial data-carrying SCs precoding(PDSP)method based on orthogonal circular matrix transform(OCT)is proposed and experimentally investigated in an intra-symbol frequency average(ISFA)-enabled discrete multi-tone(DMT)visible light communication(VLC)system.After transmission over 1.9 m free space,at the optimal bias current of 100 mA,the experimental results show that the bit error ratio(BER)performance can be improved by up to an order of magnitude with conventional full data-carrying SCs precoding(FDSP)and PDSP scheme,compared to that without a precoding scheme.Moreover,the BER performance can further be enhanced when the ISFA algorithm with optimal taps is employed.Compared with the FDSP scheme,the proposed PDSP scheme owns a similar BER performance and a significant reduction in required multiplication and addition operations,and it may be a good option to efficiently combat the unbalanced impairments of DMT-VLC transmission systems.展开更多
In this Letter,we have experimentally verified a low-complexity subcarrier pairwise-averaging(SPA)-enhanced channel estimation(CE)method for small-size fast Fourier transform(FFT)non-Hermitian symmetric orthogonal fre...In this Letter,we have experimentally verified a low-complexity subcarrier pairwise-averaging(SPA)-enhanced channel estimation(CE)method for small-size fast Fourier transform(FFT)non-Hermitian symmetric orthogonal frequency-division multiplexing(NHS-OFDM)transceivers.Compared with intra-symbol frequency averaging(ISFA),more than 20% look-up tables and 10%logic power consumption can be saved.The least-square(LS),ISFA,and SPA CE methods are compared by offline and real-time digital signal processing approaches.The results show that the receiver sensitivity of the SPA NHS-OFDM transmission system with 64/128-point FFT can be improved by more than 1 dB at the bit error rate of 3.8 ×10^(-3) compared to the LS.展开更多
基金supported by the Scientific Research Fund of Hunan Provincial Education Department(Nos.20B330 and 21A0562)the Construct Program of the Key Discipline in Hunan Province,China。
文摘To overcome the unbalanced signal-to-noise ratio(SNR)among data-carrying subcarriers(SCs)induced by the imperfect frequency response of optoelectronic devices and various interferences,a channel-independent partial data-carrying SCs precoding(PDSP)method based on orthogonal circular matrix transform(OCT)is proposed and experimentally investigated in an intra-symbol frequency average(ISFA)-enabled discrete multi-tone(DMT)visible light communication(VLC)system.After transmission over 1.9 m free space,at the optimal bias current of 100 mA,the experimental results show that the bit error ratio(BER)performance can be improved by up to an order of magnitude with conventional full data-carrying SCs precoding(FDSP)and PDSP scheme,compared to that without a precoding scheme.Moreover,the BER performance can further be enhanced when the ISFA algorithm with optimal taps is employed.Compared with the FDSP scheme,the proposed PDSP scheme owns a similar BER performance and a significant reduction in required multiplication and addition operations,and it may be a good option to efficiently combat the unbalanced impairments of DMT-VLC transmission systems.
基金This work was supported in part by the National Natural Science Foundation of China(No.61805079)the Hunan Provincial Natural Science Foundation(No.2020JJ4433)the Hunan Province College Students Research Learning and Innovative Experiment Project,China(No.S202010542058).
文摘In this Letter,we have experimentally verified a low-complexity subcarrier pairwise-averaging(SPA)-enhanced channel estimation(CE)method for small-size fast Fourier transform(FFT)non-Hermitian symmetric orthogonal frequency-division multiplexing(NHS-OFDM)transceivers.Compared with intra-symbol frequency averaging(ISFA),more than 20% look-up tables and 10%logic power consumption can be saved.The least-square(LS),ISFA,and SPA CE methods are compared by offline and real-time digital signal processing approaches.The results show that the receiver sensitivity of the SPA NHS-OFDM transmission system with 64/128-point FFT can be improved by more than 1 dB at the bit error rate of 3.8 ×10^(-3) compared to the LS.
