强干扰下跳频信号的提取

It is hard to extract frequency hopping(FH) signal under strong interf erence. An extraction method of FH signal is proposed based on image processing technology and noise peak finding. Based on Short Time Fourier Transform(STFT) time frequency spe ctrum, a noise floor estimation method based on morphological image processing is modi fied. After noise removing, the number of signals and corresponding frequencies on each time instant are estimated. Finally, characteristics of FH signal are picked up to eliminate the strong interference according to its duration. Simu lat ions show that this method can preferably pick up characteristics of FH signal w ith strong interferences existing.     

Advance the Innovation Capability and Strength of Enterprises ——Interview of NPC Deputy,Ou Jinping

As a representative from the education community, NPC Deputy, Member of the Chinese Academy of Engineering and President of the Dalian University of Technology, Ou Jinping proposed during the ＂two sessions＂ that we should improve the innovation capability and technical strength of enterprises to make them the driving force behind the development of new technology.     

Finite Element Method for Inhomogeneous Axisymmetric Resonators

A finite element method(FEM) with hybrid nodal and edge basis functio ns for solving non axisymmetric modes in axisymmetric resonators filled with in homogeneous media is presented. Spurious modes can be reduced by choosing proper basis functions. Several numerical results are presented to show the validity a nd the efficiency of proposed method.This method can be widely used in electroma gnetic(EM) engineering design.     

ICI Suppression Methods Based on Maximum Likelihood Sequence Estimation for MSDD OFDM Systems

To suppress the intercarrier interference(ICI) in multiple symbol dif ferential detection(MSDD) orthogonal frequency division multiplexing(OFDM) sys tems, statistical effects of ICI are analysed and then considered in the maximum likelihood sequence estimation(MLSE) process. Afterwards, a method, which can estimate and suppress the ICI by utilizing the knowledge of all the subcarriers in the MLSE process, is proposed. To reduce the computational complexity, severa l suboptimal ICI suppression methods, which utilize the knowledge of part of the subcarriers, are further proposed. Simulation results show that the proposed su boptimal methods can significantly enhance the bit error rate(BER) performances in both flat and frequency selective Rayleigh fading channels.     

Hybrid FEM-FIPWA for Scattering from Complex Bodies of Revolution

A method based on hybrid finite element method(FEM) and fast inhomogeneous pla ne wave algorithm (FIPWA) is proposed to solve the electromagnetic scattering pr oblem for bodies of revolution (BOR) with inhomogeneous, composite materials. Th e FEM with mixed edge based and node based elements is used for representing t he interior electric field, while the FIPWA is used as the exact boundary condit ion, hybrid triangular and pulse basis functions are used for representing the e lectric field and magnetic field on the boundary. Both the memory and CPU time r equirements are reduced for large scale BOR problems. Numerical results are give n to demonstrate the validity and the efficiency of the proposed method.     

Happy New Year of The...What?

Every person is indeed looking for strength and success in their lives.As the last of the fireworks blasts off its sparklv salute to mark the turn of the New Year,we say farewell to the graceful strength which galloped in on the Year of the Horse,and warmly welcome the Year of the Sheep.Sparks of debate have fired heavy discussions     

New Features of Chinese Cross-Border E-Commerce: Branded,Refined and Diversified

China’s cross-border e-commerce industry was dynamic in 2019,with pressing requirements being laid down on capital,technology and services,and the threshold and operation difficulty of this industry being raised to a higher level.More traditional enterprises and brands began to move towards center stage,causing China’s cross-border e-commerce sector to become refined,branded,localized and diversified.It can be said that the industry has entered a transitional period and has encountered a new situation where the driving force of development is called for.     

China Raises Tax Threshold for Domestic Firms

China has doubled the tax threshold for domestic firms in a move to narrow the taxation gap between indigenous and foreign-invested companies, the State Administration of Taxation (SAT) said on September 8.     

LAW

Specific guidelines set for new Anti-Monopoly Law The first regulation that sets specific guidelines for the Anti-Monopoly Law was announced by the State Council late on August 4 in a move to provide guide- lines and direction for the enforcement of the law, which came into effect on Au- gust 1. According to the regulations, all combinations must apply to authorities in charge of anti-monopoly if the joint global revenue of the companies involved exceeds RMB 10 billion or if revenue in China exceeds RMB 2 billion.     

Investing in SADC

"Cihina is willing to in-crease the imports from the SADC, encourage enterprises with strength and good reputation to invest in SADC countries.Both sides should further strengthen cooperation in economy and trade, investment, finance, energy resources, infrastructure and other fields, to realize mutual benefits and the win-win," said Chinese vice premier Wang Qishan recently on the opening ceremony for China and Southern African Development Community (SADC) Economic and Trade Forum. This is the first time for China, the largest trade partner of SADC, to hold a forum for entrepreneurs and investors from both sides in Beijing and investors, aiming at further promoting the trade and investment.Chinese vice Premier Wang Qishan and Pohamba, rotating chairman of SADC and president of Namibia, attended the ceremony and made speeches.Under the witness of Wang and Pohamba, CCPIT and the secretariat of SADC signed cooperation documents.