Research And FPGA Implementation For Receiving Technique Of High Dynamic Short Burst Signal

In recent years,with the development of electromagnetisms,aerodynamics and system controls,high-speed aircraft technology has great progress in the area of dynamic communication,simultaneously the high dynamic communication link has caused continuous attention.Different from the conventional communication link,both sides of the high dynamic communication link not only have long distance,but also have high relative speed and strong maneuverability.The long distance would cause lower input signal power spectral density of the receiver.The high relative speed would cause the input signal of the receiver to have large frequency shift.The strong maneuverability would lead the input signal of the receiver to vary in a wide range of fluctuations in the aspects of power,the ratio of signal to noise(SNR)and the frequency shift.There is no doubt that the above situation creates a very severe demand for the signal processing capabilities at the receiver.Faced aforementioned situation,this thesis investigates the key technology of high dynamic short burst signal reception and proposes a real-time synchronization acquisition algorithm which is suitable for low SNR,large frequency shift and high dynamic condition.Based on this research,this thesis puts forward a set of scheme for the baseband unit of the short burst spread spectrum communication system and carries out the scheme with FPGA hardware platform under the background of the "XXX data link" project.The main contents and work of this thesis are as follows:1.In this thesis,burst communication technology,synchronous capture technology,spread spectrum technology and some key technologies involved in wireless communication systems are discussed.Meanwhile,this thesis also investigates on the conventional real-time synchronization acquisition technique based on the characteristics of high dynamic short burst signal.A new real-time synchronization acquisition algorithm base on PMF-FFT is proposed.The algorithm can accurately complete the real-time synchronization acquisition of short burst signals under low SNR,large frequency offset and high dynamic condition,which meets the demands of this project.2.According to the requirements of the project,this thesis puts forward a set of scheme for the baseband unit of the short burst spread spectrum communication system which suits for low SNR,large frequency shift and high dynamic condition.Furthermore,this thesis demonstrates the rationality of the scheme in the aspects of theoretical basis,performance and implementation complexity and gives the corresponding simulation results.3.The proposed scheme is implemented by using Verilog HDL at the FPGA hardware platform.Futhermore,a series of tests are accomplished through the customized prototype.The test results show that the whole system can work stably at the clock rate of 80 M.Moreover,the length of time slice,band width and frame error rate also meet the requirement of our proposed structure.