A method utilizing single channel recordings to blindly separate the multicomponents overlapped in time and frequency domains is proposed in this paper. Based on the time varying AR model, the instantaneous frequency ...A method utilizing single channel recordings to blindly separate the multicomponents overlapped in time and frequency domains is proposed in this paper. Based on the time varying AR model, the instantaneous frequency and amplitude of each signal component are estimated respectively, thus the signal component separation is achieved. By using prolate spheroidal sequence as basis functions to expand the time varying parameters of the AR model, the method turns the problem of linear time varying parameters estimation to a linear time invariant parameter estimation problem, then the parameters are estimated by a recursive algorithm. The computation of this method is simple, and no prior knowledge of the signals is needed. Simulation results demonstrate validity and excellent performance of this method.展开更多
We experimentally demonstrate a direct-detection orthogonal-frequency-division-multiplexing quadraturephase-shift-keying（OFDM-QPSK） system that is capable of delivering a 32 Gbaud OFDM-QPSK signal over7 km single-mo...We experimentally demonstrate a direct-detection orthogonal-frequency-division-multiplexing quadraturephase-shift-keying（OFDM-QPSK） system that is capable of delivering a 32 Gbaud OFDM-QPSK signal over7 km single-mode fiber-28（SMF-28）. Intra-symbol frequency-domain averaging（ISFA） channel response estimation is applied to suppress in-band noise,while discrete Fourier transform-spread（DFT-spread） is used to reduce the peak-to-average power ratio（PAPR） of the transmitted OFDM signal. With the aid of ISFA-based channel estimation and PAPR reduction enabled by DFT-spread,the bit-error ratio of the system after 7 km SMF-28 transmission can be improved from 2×10^-3 to error-free when the received optical power is -8.5 d Bm.展开更多
基金Supported by the Program for New Century Excellent Talents in University, Ministry of Education, China (Grant No. NCET-05-0803)
文摘A method utilizing single channel recordings to blindly separate the multicomponents overlapped in time and frequency domains is proposed in this paper. Based on the time varying AR model, the instantaneous frequency and amplitude of each signal component are estimated respectively, thus the signal component separation is achieved. By using prolate spheroidal sequence as basis functions to expand the time varying parameters of the AR model, the method turns the problem of linear time varying parameters estimation to a linear time invariant parameter estimation problem, then the parameters are estimated by a recursive algorithm. The computation of this method is simple, and no prior knowledge of the signals is needed. Simulation results demonstrate validity and excellent performance of this method.
文摘We experimentally demonstrate a direct-detection orthogonal-frequency-division-multiplexing quadraturephase-shift-keying（OFDM-QPSK） system that is capable of delivering a 32 Gbaud OFDM-QPSK signal over7 km single-mode fiber-28（SMF-28）. Intra-symbol frequency-domain averaging（ISFA） channel response estimation is applied to suppress in-band noise,while discrete Fourier transform-spread（DFT-spread） is used to reduce the peak-to-average power ratio（PAPR） of the transmitted OFDM signal. With the aid of ISFA-based channel estimation and PAPR reduction enabled by DFT-spread,the bit-error ratio of the system after 7 km SMF-28 transmission can be improved from 2×10^-3 to error-free when the received optical power is -8.5 d Bm.
