Worldwide Interoperability for Microwave Access (WiMAX) technology has rapidly developed in recent years. It is becoming one of the hotspots among broadband wireless access technologies. A WiMAX system can provide ban...Worldwide Interoperability for Microwave Access (WiMAX) technology has rapidly developed in recent years. It is becoming one of the hotspots among broadband wireless access technologies. A WiMAX system can provide bandwidth efficiency higher than 2 bps/Hz. In order to improve coverage and reliability of the WiMAX system,the IEEE 802.16 standard supports multiple antenna techniques such as Alamouti Space-Time Coding (STC),Adaptive Antenna System (AAS) and Multiple Input Multiple Output (MIMO). The applications of the multiple antenna techniques improve system capacity and bandwidth efficiency significantly,and enhance the competence of the WiMAX technology greatly.展开更多
In this paper,high-uniformity 2×64 silicon avalanche photodiode[APD]arrays are reported.Silicon multiple epitaxy technology was used,and the high performance APD arrays based on double-layer epiwafers are achieve...In this paper,high-uniformity 2×64 silicon avalanche photodiode[APD]arrays are reported.Silicon multiple epitaxy technology was used,and the high performance APD arrays based on double-layer epiwafers are achieved for the first time,to the best of our knowledge.A high-uniformity breakdown voltage with a fluctuation of smaller than 3.5 V is obtained for the fabricated APD arrays.The dark currents are below 90 pA for all 128 pixels at unity gain voltage.The pixels in the APD arrays show a gain factor of larger than 300 and a peak responsivity of 0.53 A/W@M=1 at 850 nm[corresponding to maximum external quantum efficiency of 81%]at room temperature.Quick optical pulse response time was measured,and a corresponding cutoff frequency up to 100 MHz was obtained.展开更多
In order to establish an accurate peak over threshold(POT)model for reasonable load extrapolation,a new threshold selection method based on multiple criteria decision making(MCDM)technology is proposed.The fitting tes...In order to establish an accurate peak over threshold(POT)model for reasonable load extrapolation,a new threshold selection method based on multiple criteria decision making(MCDM)technology is proposed.The fitting test criterion is taken into consideration in the method.For each candidate threshold,the fitting values of several fitting test criteria are integrated into a comprehensive evaluation value through entropy method and MCDM technology.The threshold corresponding to the minimum comprehensive evaluation value is assumed as the optimal threshold.A random simulation study is carried out to evaluate the performance of the method and to compare them with other literature methods.Genuine load data are applied the proposed method.Both the results shown that the proposed method could be seen as an additional method that complements existing threshold selection methods.展开更多
文摘Worldwide Interoperability for Microwave Access (WiMAX) technology has rapidly developed in recent years. It is becoming one of the hotspots among broadband wireless access technologies. A WiMAX system can provide bandwidth efficiency higher than 2 bps/Hz. In order to improve coverage and reliability of the WiMAX system,the IEEE 802.16 standard supports multiple antenna techniques such as Alamouti Space-Time Coding (STC),Adaptive Antenna System (AAS) and Multiple Input Multiple Output (MIMO). The applications of the multiple antenna techniques improve system capacity and bandwidth efficiency significantly,and enhance the competence of the WiMAX technology greatly.
基金supported by the National Science and Technology Major Project(No.2018YFE0200900)。
文摘In this paper,high-uniformity 2×64 silicon avalanche photodiode[APD]arrays are reported.Silicon multiple epitaxy technology was used,and the high performance APD arrays based on double-layer epiwafers are achieved for the first time,to the best of our knowledge.A high-uniformity breakdown voltage with a fluctuation of smaller than 3.5 V is obtained for the fabricated APD arrays.The dark currents are below 90 pA for all 128 pixels at unity gain voltage.The pixels in the APD arrays show a gain factor of larger than 300 and a peak responsivity of 0.53 A/W@M=1 at 850 nm[corresponding to maximum external quantum efficiency of 81%]at room temperature.Quick optical pulse response time was measured,and a corresponding cutoff frequency up to 100 MHz was obtained.
基金National Natural Science Foundation of China(No.51375202).
文摘In order to establish an accurate peak over threshold(POT)model for reasonable load extrapolation,a new threshold selection method based on multiple criteria decision making(MCDM)technology is proposed.The fitting test criterion is taken into consideration in the method.For each candidate threshold,the fitting values of several fitting test criteria are integrated into a comprehensive evaluation value through entropy method and MCDM technology.The threshold corresponding to the minimum comprehensive evaluation value is assumed as the optimal threshold.A random simulation study is carried out to evaluate the performance of the method and to compare them with other literature methods.Genuine load data are applied the proposed method.Both the results shown that the proposed method could be seen as an additional method that complements existing threshold selection methods.
