In optical coherent receivers,the timing error detector （TED） in synchronization loop can not work normally when signal is distorted by large dispersion.This paper proposes a novel clock synchronization scheme which...In optical coherent receivers,the timing error detector （TED） in synchronization loop can not work normally when signal is distorted by large dispersion.This paper proposes a novel clock synchronization scheme which adds a butterfly-structured adaptive equalizer to the loop to fulfill synchronizations,equalizations and polarization de-multiplexing of two polarization states simultaneously under the control of single voltage-controlled oscillator （VCO）.Simulink simulation demonstrates the rationality and the feasibility of the combined loop with single VCO.展开更多
An adaptive algorithm named low complexity phase off- set estimation （LC-POE） is proposed for orthogonal frequency division multiplexing （OFDM） signals. Depending on the requirement, the estimation procedure is di...An adaptive algorithm named low complexity phase off- set estimation （LC-POE） is proposed for orthogonal frequency division multiplexing （OFDM） signals. Depending on the requirement, the estimation procedure is divided into several scales to accelerate the adaptive convergence speed and ensure the estimation accuracy. The true phase offset is estimated through shrinking the detection range and raising the resolution scale step by step. Both the convergence performance and complexity are discussed in the paper. Simulation results show the effectiveness of the proposed algorithm. The LC-POE algorithm is promising in the application of OFDM systems.展开更多
In this paper, we propose a novel superreceiver architecture for Nyquistwavelengthdivision multiplexing （WDM） superchannel optical coherent systems. As opposed to a conventional coherent receiver, where each subchan...In this paper, we propose a novel superreceiver architecture for Nyquistwavelengthdivision multiplexing （WDM） superchannel optical coherent systems. As opposed to a conventional coherent receiver, where each subchannel is demodulated independently, the proposed superreceiver jointly detects and demodulates multiple subchannels simultaneously. By taking advantage of information from side channels that use joint DSP to cancel interchannel interference （ICI）, the proposed super receiver performs much better than a conventional receiver. This architecture also has the potential to compensate for crosschannel impairments caused by linear and nonlinear effects. We examine the proposed architecture through experiment and simulation. OSNR is improved by more than 5 dB after 1280 km fiber transmission with narrow channel spacing.展开更多
A spectrally sliced heterodyne coherent receiver(SHCR)employing four balanced photodetectors and analog-to-digital converters with half of the signal bandwidth is proposed to complete the signal reception and field re...A spectrally sliced heterodyne coherent receiver(SHCR)employing four balanced photodetectors and analog-to-digital converters with half of the signal bandwidth is proposed to complete the signal reception and field recovery.We first numerically characterize the performance of SHCR compared with an intradyne coherent receiver and then validate the principle of the SHCR in a proof-of-concept single-polarization experiment.A 60 GBaud 16-quadrature amplitude modulation transmission is experimentally demonstrated over 80 km standard single-mode fiber with a bit-error-rate of 8.5×10^(-4) below the 7%hard-decision forward error correction threshold of 3.8×10^(-3).The SHCR offers a low-cost,hybrid-free,and channel-skew-tolerant candidate for data center interconnects.展开更多
基金supported by the Hi-Tech Research and Development Program of China (2009AA01Z221)the National Natural Science Foundation of China (61072053)
文摘In optical coherent receivers,the timing error detector （TED） in synchronization loop can not work normally when signal is distorted by large dispersion.This paper proposes a novel clock synchronization scheme which adds a butterfly-structured adaptive equalizer to the loop to fulfill synchronizations,equalizations and polarization de-multiplexing of two polarization states simultaneously under the control of single voltage-controlled oscillator （VCO）.Simulink simulation demonstrates the rationality and the feasibility of the combined loop with single VCO.
基金supported by the National Natural Science Foundation of China (60972072)the National Science and Technology Major Projects: the New Generation Broadband Wireless Mobile Communication Network (2009ZX03003-03)the "111 Project" of China (B08038)
文摘An adaptive algorithm named low complexity phase off- set estimation （LC-POE） is proposed for orthogonal frequency division multiplexing （OFDM） signals. Depending on the requirement, the estimation procedure is divided into several scales to accelerate the adaptive convergence speed and ensure the estimation accuracy. The true phase offset is estimated through shrinking the detection range and raising the resolution scale step by step. Both the convergence performance and complexity are discussed in the paper. Simulation results show the effectiveness of the proposed algorithm. The LC-POE algorithm is promising in the application of OFDM systems.
文摘In this paper, we propose a novel superreceiver architecture for Nyquistwavelengthdivision multiplexing （WDM） superchannel optical coherent systems. As opposed to a conventional coherent receiver, where each subchannel is demodulated independently, the proposed superreceiver jointly detects and demodulates multiple subchannels simultaneously. By taking advantage of information from side channels that use joint DSP to cancel interchannel interference （ICI）, the proposed super receiver performs much better than a conventional receiver. This architecture also has the potential to compensate for crosschannel impairments caused by linear and nonlinear effects. We examine the proposed architecture through experiment and simulation. OSNR is improved by more than 5 dB after 1280 km fiber transmission with narrow channel spacing.
基金supported by the National Natural Science Foundation of China(No.62001287)National Key R&D Program of China(No.2018YFB1800904)。
文摘A spectrally sliced heterodyne coherent receiver(SHCR)employing four balanced photodetectors and analog-to-digital converters with half of the signal bandwidth is proposed to complete the signal reception and field recovery.We first numerically characterize the performance of SHCR compared with an intradyne coherent receiver and then validate the principle of the SHCR in a proof-of-concept single-polarization experiment.A 60 GBaud 16-quadrature amplitude modulation transmission is experimentally demonstrated over 80 km standard single-mode fiber with a bit-error-rate of 8.5×10^(-4) below the 7%hard-decision forward error correction threshold of 3.8×10^(-3).The SHCR offers a low-cost,hybrid-free,and channel-skew-tolerant candidate for data center interconnects.
