| As a new type of frequency hopping technology,Different Frequency Hopping(DFH)has received extensive attention in the field of military communications.With the increasing trend of wireless communication bandwidth,the sampling rate of ADC devices is facing more and more severe challenges and will limits the DFH system to work over a wider spectrum.The emergence of compressed sensing theory,especially Analog to Information Converter(AIC)technology which is directly applied to analog signals,enables ADC devices to sample ultra-wideband signals at a sub-Nyquist rate,then it’s ensured that the original signal is constructed with high probability.Based on AIC technology,this paper attempts to apply CS theory to DFH system,and proposes AIC-DFH technology and AIC-Turbo-DFH technology.There is a difference between AIC-DFH and conventional DFH,an AIC module capable of compressive sampling is used in AICDFH while a FFT module based on the Nyquist sampling theorem is used in conventional DFH system.In this way,AIC-DFH may work on a wider spectrum,and ADC devices do not have to pay a high price for sampling rate.At the same time,by selecting the appropriate algorithm,the computational complexity of the AIC module will be lower than that of the FFT module.This paper proposes a DFH receiver model based on AIC technology,and gives a metric calculation method based on least square method and inner product.Then analyze the complexity of AIC-DFH and compare the simulation performance of conventional DFH and AIC-DFH.This paper further applies Turbo codes to AIC-DFH receivers and proposes AICTurbo-DFH technology.Firstly,the decoding process of a Turbo-DFH system based on polynomial G-function generated from convolutional codes is deduced.Then we give the receiver model of AIC-Turbo-DFH and the corresponding code structure.Simulation analysis of the effect of different interleaving length and number of iterations of the decoder on system performance,as well as compare the simulation performance of conventional Turbo-DFH and AIC-Turbo-DFH.There are six chapters in this paper.The first chapter mainly describes the research value of applying AIC technology to DFH signal processing.The second chapter mainly expounds the basic theory of compressed sensing,the construction of G function based on the generator polynomial of convolutional code,and the sparseness of DFH signal.The third chapter gives the matrix form of CS theoretical model of analog signal,and lays the theoretical foundation of AIC technology.The fourth chapter first proposes AIC-DFH technology,and gives the calculation process of using AIC module to provide metrics for frequency sequence decoding module.The fifth chapter first elaborates on the compile-code structure of Turbo-DFH system,then applies AIC technology to Turbo-DFH,proposes AIC-Turbo-DFH technology,and gives the working principle of AIC-Turbo-DFH.The sixth chapter summarizes the full text and gives some suggestions for future research. |
