As modern electromagnetic environments are more and more complex,the anti-interference performance of the synchronization acquisition is becoming vital in wireless communications.With the rapid development of the digi...As modern electromagnetic environments are more and more complex,the anti-interference performance of the synchronization acquisition is becoming vital in wireless communications.With the rapid development of the digital signal processing technologies,some synchronization acquisition algorithms for hybrid direct-sequence(DS)/frequency hopping(FH)spread spectrum communications have been proposed.However,these algorithms do not focus on the analysis and the design of the synchronization acquisition under typical interferences.In this paper,a synchronization acquisition algorithm based on the frequency hopping pulses combining(FHPC)is proposed.Specifically,the proposed algorithm is composed of two modules:an adaptive interference suppression(IS)module and an adaptive combining decision module.The adaptive IS module mitigates the effect of the interfered samples in the time-domain or the frequencydomain,and the adaptive combining decision module can utilize each frequency hopping pulse to construct an anti-interference decision metric and generate an adaptive acquisition decision threshold to complete the acquisition.Theory and simulation demonstrate that the proposed algorithm significantly enhances the antiinterference and anti-noise performances of the synchronization acquisition for hybrid DS/FH communications.展开更多
通过水热法合成了Co_(5)Ni_(1)O_(x)/碳布(CC)电催化剂,研究了其微观结构、析氧反应/析氢反应电催化性能和电解水性能,并与Co_(6)O_(x)/CC、Ni_(6)O_(x)/CC以及商业Ru O_(2)和Pt/C电催化剂进行对比。结果表明:Co_(5)Ni_(1)O_(x)/CC试样...通过水热法合成了Co_(5)Ni_(1)O_(x)/碳布(CC)电催化剂,研究了其微观结构、析氧反应/析氢反应电催化性能和电解水性能,并与Co_(6)O_(x)/CC、Ni_(6)O_(x)/CC以及商业Ru O_(2)和Pt/C电催化剂进行对比。结果表明:Co_(5)Ni_(1)O_(x)/CC试样中的Co_(5)Ni_(1)O_(x)纳米棒负载于碳布表面;在电流密度为10 m A·cm^(-2)时,Co_(5)Ni_(1)O_(x)/CC试样发生析氧反应的过电位为289 m V,明显低于Co_(6)O_(x)/CC试样、Ni_(6)O_(x)/CC试样和Ru O_(2)电催化剂(342,405,422 m V),发生析氢反应的过电位为200 m V,低于Co_(6)O_(x)/CC试样和Ni_(6)O_(x)/CC试样(252,364 m V),更接近Pt/C电催化剂(44 m V);Co_(5)Ni_(1)O_(x)/CC试样组装的电解水槽电压为1.69 V,低于分别由Co_(6)O_(x)/CC和Ni_(6)O_(x)/CC试样组装的电解水槽电压(1.78,1.85 V),与Ru O_(2)和Pt/C电催化剂分别作为阳极与阴极组装的电解水槽电压相近(1.70 V)。展开更多
基金supported in part by the National Natural Science Foundation of China (NSFC) under Grants 62131005, 62071096in part by the Fundamental Research Funds for the Central Universities under Grant 2242022k60006+1 种基金in part by the National NSFC under Grant U19B2014in part by the Natural Science Foundation of Sichuan under Grant 2022NSFSC0495
文摘As modern electromagnetic environments are more and more complex,the anti-interference performance of the synchronization acquisition is becoming vital in wireless communications.With the rapid development of the digital signal processing technologies,some synchronization acquisition algorithms for hybrid direct-sequence(DS)/frequency hopping(FH)spread spectrum communications have been proposed.However,these algorithms do not focus on the analysis and the design of the synchronization acquisition under typical interferences.In this paper,a synchronization acquisition algorithm based on the frequency hopping pulses combining(FHPC)is proposed.Specifically,the proposed algorithm is composed of two modules:an adaptive interference suppression(IS)module and an adaptive combining decision module.The adaptive IS module mitigates the effect of the interfered samples in the time-domain or the frequencydomain,and the adaptive combining decision module can utilize each frequency hopping pulse to construct an anti-interference decision metric and generate an adaptive acquisition decision threshold to complete the acquisition.Theory and simulation demonstrate that the proposed algorithm significantly enhances the antiinterference and anti-noise performances of the synchronization acquisition for hybrid DS/FH communications.
文摘通过水热法合成了Co_(5)Ni_(1)O_(x)/碳布(CC)电催化剂,研究了其微观结构、析氧反应/析氢反应电催化性能和电解水性能,并与Co_(6)O_(x)/CC、Ni_(6)O_(x)/CC以及商业Ru O_(2)和Pt/C电催化剂进行对比。结果表明:Co_(5)Ni_(1)O_(x)/CC试样中的Co_(5)Ni_(1)O_(x)纳米棒负载于碳布表面;在电流密度为10 m A·cm^(-2)时,Co_(5)Ni_(1)O_(x)/CC试样发生析氧反应的过电位为289 m V,明显低于Co_(6)O_(x)/CC试样、Ni_(6)O_(x)/CC试样和Ru O_(2)电催化剂(342,405,422 m V),发生析氢反应的过电位为200 m V,低于Co_(6)O_(x)/CC试样和Ni_(6)O_(x)/CC试样(252,364 m V),更接近Pt/C电催化剂(44 m V);Co_(5)Ni_(1)O_(x)/CC试样组装的电解水槽电压为1.69 V,低于分别由Co_(6)O_(x)/CC和Ni_(6)O_(x)/CC试样组装的电解水槽电压(1.78,1.85 V),与Ru O_(2)和Pt/C电催化剂分别作为阳极与阴极组装的电解水槽电压相近(1.70 V)。