Blockchain technology is a core,underlying technology with promising application prospects in the banking industry.On one hand,the banking industry in China is facing the impact of interest rate liberalization and pro...Blockchain technology is a core,underlying technology with promising application prospects in the banking industry.On one hand,the banking industry in China is facing the impact of interest rate liberalization and profit decline caused by the narrowing interest-rate spread.On the other hand,it is also affected by economic transformation,Internet development,and financial innovations.Hence,the banking industry requires urgent transformation and is seeking new growth avenues.As such,blockchains could revolutionize the underlying technology of the payment clearing and credit information systems in banks,thus upgrading and transforming them.Blockchain applications also promote the formation of“multi-center,weakly intermediated”scenarios,which will enhance the efficiency of the banking industry.However,despite the permissionless and self-governing nature of blockchains,the regulation and actual implementation of a decentralized system are problems that remain to be resolved.Therefore,we propose the urgent establishment of a“regulatory sandbox”and the development of industry standards.展开更多
In this paper,a Doppler scaling fast Fourier transform(Doppler-FFT)algorithm for filter bank multi-carrier(FBMC)is proposed,which can efficiently eliminate the impact of the Doppler scaling in satellite communicat...In this paper,a Doppler scaling fast Fourier transform(Doppler-FFT)algorithm for filter bank multi-carrier(FBMC)is proposed,which can efficiently eliminate the impact of the Doppler scaling in satellite communications.By introducing a Doppler scaling factor into the butterfly structure of the fast Fourier transform(FFT)algorithm,the proposed algorithm eliminates the differences between the Doppler shifts of the received subcarriers,and maintains the same order of computational complexity compared to that of the traditional FFT.In the process of using the new method,the Doppler scaling should be estimated by calculating the orbital data in advance.Thus,the inter-symbol interference(ISI)and the inter-carrier interference(ICI)can be completely eliminated,and the signal to interference and noise ratio(SINR)will not be affected.Simulation results also show that the proposed algorithm can achieve a 0.4 d B performance gain compared to the frequency domain equalization(FDE)algorithm in satellite communications.展开更多
Estimating cross-range velocity is a challenging task for space-borne synthetic aperture radar(SAR), which is important for ground moving target indication(GMTI). Because the velocity of a target is very small com...Estimating cross-range velocity is a challenging task for space-borne synthetic aperture radar(SAR), which is important for ground moving target indication(GMTI). Because the velocity of a target is very small compared with that of the satellite, it is difficult to correctly estimate it using a conventional monostatic platform algorithm. To overcome this problem, a novel method employing multistatic SAR is presented in this letter. The proposed hybrid method, which is based on an extended space-time model(ESTIM) of the azimuth signal, has two steps: first, a set of finite impulse response(FIR) filter banks based on a fractional Fourier transform(FrFT) is used to separate multiple targets within a range gate; second, a cross-correlation spectrum weighted subspace fitting(CSWSF) algorithm is applied to each of the separated signals in order to estimate their respective parameters. As verified through computer simulation with the constellations of Cartwheel, Pendulum and Helix, this proposed time-frequency-subspace method effectively improves the estimation precision of the cross-range velocities of multiple targets.展开更多
文摘Blockchain technology is a core,underlying technology with promising application prospects in the banking industry.On one hand,the banking industry in China is facing the impact of interest rate liberalization and profit decline caused by the narrowing interest-rate spread.On the other hand,it is also affected by economic transformation,Internet development,and financial innovations.Hence,the banking industry requires urgent transformation and is seeking new growth avenues.As such,blockchains could revolutionize the underlying technology of the payment clearing and credit information systems in banks,thus upgrading and transforming them.Blockchain applications also promote the formation of“multi-center,weakly intermediated”scenarios,which will enhance the efficiency of the banking industry.However,despite the permissionless and self-governing nature of blockchains,the regulation and actual implementation of a decentralized system are problems that remain to be resolved.Therefore,we propose the urgent establishment of a“regulatory sandbox”and the development of industry standards.
基金supported by the National Natural Science Foundation of China (No. 91438116)by the Program for New Century Excellent Talents in University of China (No. NCET-12-0030)+1 种基金by the National Hi-Tech R&D Program of China (No. 2015AA7014065)by the Shanghai Aerospace Science and Technology Innovation Fund (No. SAST2015089)
文摘In this paper,a Doppler scaling fast Fourier transform(Doppler-FFT)algorithm for filter bank multi-carrier(FBMC)is proposed,which can efficiently eliminate the impact of the Doppler scaling in satellite communications.By introducing a Doppler scaling factor into the butterfly structure of the fast Fourier transform(FFT)algorithm,the proposed algorithm eliminates the differences between the Doppler shifts of the received subcarriers,and maintains the same order of computational complexity compared to that of the traditional FFT.In the process of using the new method,the Doppler scaling should be estimated by calculating the orbital data in advance.Thus,the inter-symbol interference(ISI)and the inter-carrier interference(ICI)can be completely eliminated,and the signal to interference and noise ratio(SINR)will not be affected.Simulation results also show that the proposed algorithm can achieve a 0.4 d B performance gain compared to the frequency domain equalization(FDE)algorithm in satellite communications.
基金supported by the National Natural Science Foundation of China (No. 61271343)the Research Fund for the Doctoral Program of Higher Education of China (No. 20122302110012)the 2014 Innovation of Science and Technology Program of China Aerospace Science and Technology Corporation
文摘Estimating cross-range velocity is a challenging task for space-borne synthetic aperture radar(SAR), which is important for ground moving target indication(GMTI). Because the velocity of a target is very small compared with that of the satellite, it is difficult to correctly estimate it using a conventional monostatic platform algorithm. To overcome this problem, a novel method employing multistatic SAR is presented in this letter. The proposed hybrid method, which is based on an extended space-time model(ESTIM) of the azimuth signal, has two steps: first, a set of finite impulse response(FIR) filter banks based on a fractional Fourier transform(FrFT) is used to separate multiple targets within a range gate; second, a cross-correlation spectrum weighted subspace fitting(CSWSF) algorithm is applied to each of the separated signals in order to estimate their respective parameters. As verified through computer simulation with the constellations of Cartwheel, Pendulum and Helix, this proposed time-frequency-subspace method effectively improves the estimation precision of the cross-range velocities of multiple targets.