The performance of a wavelength-division multiplexing (WDM) free-space optical (FSO) commu-nication system in a turbulent atmosphere employing optical amplifiers to improve capacity is investigated, in the presence of...The performance of a wavelength-division multiplexing (WDM) free-space optical (FSO) commu-nication system in a turbulent atmosphere employing optical amplifiers to improve capacity is investigated, in the presence of amplified spontaneous emission noise, scintillation, beam spreading, atmospheric attenuation and interchannel crosstalk. Using on-off keying modulation, Monte Carlo simulation techniques are used to obtain the average bit error rate and system capability due to scintillation and the effect of introducing a power control algorithm (PCA) to the system is investigated. The PCA ensures that at any receiving instant, the same turbulence- free powers are received by all the receiving lenses. The performance of various WDM FSO communication system configurations such as non-amplified systems with an adaptive decision threshold (NOAADT), non- amplified systems with a non-adaptive decision threshold, fixed gain amplified systems with an adaptive decision threshold, fixed gain amplified systems with a non- adaptive decision threshold and saturated gain amplified systems with a non-adaptive decision threshold (SOA- NADT) are investigated. Results obtained show that the SOANADT is superior to the NOAADT and the PCA is only beneficial in amplified systems.展开更多
提出了一种基于CAZAC(Constant Amplitude Zero Auto Correlation)的改进帧同步检测方案。首先,利用CAZAC序列作为短训练序列来改变IEEE802.11a系统标准前导结构,并增加用于粗频偏估计的短训练序列个数;其次,在使用延时相关帧检测的基础...提出了一种基于CAZAC(Constant Amplitude Zero Auto Correlation)的改进帧同步检测方案。首先,利用CAZAC序列作为短训练序列来改变IEEE802.11a系统标准前导结构,并增加用于粗频偏估计的短训练序列个数;其次,在使用延时相关帧检测的基础上,结合短训练序列的互相关信息共同完成帧同步检测。由于CAZAC序列良好的自身特性以及互相关信息的辅助,使得帧同步检测更加准确,粗频偏估计的性能也有所提高,大频偏下仍得到稳定的性能。仿真结果显示,在多径时延为100ns,频偏为200kHz时,与传统方法比较能得到约2dB的增益。展开更多
Multi-lane integrated transmitter chips are key components in future compact optical modules to realize high-speed optical interconnects.Thin-film lithium niobate(TFLN)photonics have emerged as a promising platform fo...Multi-lane integrated transmitter chips are key components in future compact optical modules to realize high-speed optical interconnects.Thin-film lithium niobate(TFLN)photonics have emerged as a promising platform for achieving high-performance chip-scale optical systems.Combining a coarse wavelength-division multiplexing(CWDM)devices using fabrication-tolerant angled multimode interferometer structure and high-performance electro-optical modulators,we demonstrate monolithic on-chip four-channel CWDM transmitter on the TFLN platform for the first time.The four-channel CWDM transmitter enables high-speed transmissions of 100 Gb/s data rate per wavelength channel(i.e.,an aggregated date rate of 400 Gb/s).展开更多
文摘The performance of a wavelength-division multiplexing (WDM) free-space optical (FSO) commu-nication system in a turbulent atmosphere employing optical amplifiers to improve capacity is investigated, in the presence of amplified spontaneous emission noise, scintillation, beam spreading, atmospheric attenuation and interchannel crosstalk. Using on-off keying modulation, Monte Carlo simulation techniques are used to obtain the average bit error rate and system capability due to scintillation and the effect of introducing a power control algorithm (PCA) to the system is investigated. The PCA ensures that at any receiving instant, the same turbulence- free powers are received by all the receiving lenses. The performance of various WDM FSO communication system configurations such as non-amplified systems with an adaptive decision threshold (NOAADT), non- amplified systems with a non-adaptive decision threshold, fixed gain amplified systems with an adaptive decision threshold, fixed gain amplified systems with a non- adaptive decision threshold and saturated gain amplified systems with a non-adaptive decision threshold (SOA- NADT) are investigated. Results obtained show that the SOANADT is superior to the NOAADT and the PCA is only beneficial in amplified systems.
文摘提出了一种基于CAZAC(Constant Amplitude Zero Auto Correlation)的改进帧同步检测方案。首先,利用CAZAC序列作为短训练序列来改变IEEE802.11a系统标准前导结构,并增加用于粗频偏估计的短训练序列个数;其次,在使用延时相关帧检测的基础上,结合短训练序列的互相关信息共同完成帧同步检测。由于CAZAC序列良好的自身特性以及互相关信息的辅助,使得帧同步检测更加准确,粗频偏估计的性能也有所提高,大频偏下仍得到稳定的性能。仿真结果显示,在多径时延为100ns,频偏为200kHz时,与传统方法比较能得到约2dB的增益。
基金This work is supported partially by the National Major Research and Development Program(2019YFB1803902)National Natural Science Foundation of China(NSFC)(62135012,62105107)+3 种基金Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(2021R01001)Guangdong Basic and Applied Basic Research Foundation(2021A 1515012215,2021B1515120057)Science and Technology Planning Project of Guangdong Province(2019A050510039)Fundamental Research Funds for the Central Universities(2021QNA5001).
文摘Multi-lane integrated transmitter chips are key components in future compact optical modules to realize high-speed optical interconnects.Thin-film lithium niobate(TFLN)photonics have emerged as a promising platform for achieving high-performance chip-scale optical systems.Combining a coarse wavelength-division multiplexing(CWDM)devices using fabrication-tolerant angled multimode interferometer structure and high-performance electro-optical modulators,we demonstrate monolithic on-chip four-channel CWDM transmitter on the TFLN platform for the first time.The four-channel CWDM transmitter enables high-speed transmissions of 100 Gb/s data rate per wavelength channel(i.e.,an aggregated date rate of 400 Gb/s).