Reserach And Implementation Of Multi-beam Interference Suppression Algorithm For GPS Receiver

Satellite navigation system provides users with high precision positioning and timing services.When the satellite signal transmiting to the surface,the signal power becomes extremely low,and the satellite navigation system is unable to provide normal service because of all kinds of the electromagnetic.In view of the high precision positioning service playing an important part in national defense military action,the research of interference suppression technology around satellite navigation system must be accelerated.At present,the interference suppression technology research is focused on the interference suppression algorithm based on array signal processing,the multi-beam interference suppression technology is an important research direction of array signal processing.This paper make the GPS satellite navigation system as the research object,at first the characteristics of the GPS satellite signal and current typical interference are analyzed,and the oppressive jamming definite as the main type of interference.The commonly constraint rules about multi-beam interference suppression technology are introduced,and the basic principles of power inversion algorithm based on the rule of linear constraint minimum variance(LCMV)is analysised.At the advantages and disadvantages of power inversion algorithm,the multiple signal classification(MUSIC)algorithm is selected to improve the rule of minimum variance constraints,with the MUSIC algorithm to estimating the direction of signal,the LCMV criterion has multi-beam constraints.At last,the performances of algorithm is analyzed in the Matlab simulation software.The simulation results show that the algorithm can accurately sank in the interference signal to zero and the satellite signal can form up gain beam.In addition,interference suppression hardware system including the antenna array,RF front-end and baseband processing board is designed,and the hardware scheme and hardware device is analyzed in detail.To reducing the hardware implementation complexity of the MUSIC-LCMV algorithm.the three key algorithm about the Householder and Givens transform transform for solving matrix eigenvalues,the minimum description length(MDL)principle to estimate the number of interference and cholesky for matrix inversion are introduced in details.Finally,under the condition of the real outdoor environment,the test compare the power inversion algorithm based on LCMV and multi-beam suppression algorithm based on MUSIC-LCMV.The results show that MUSIC-LCMV algorithm performance stable,and the ability of the interference suppression is increased nearly 10dB and reached at 80dB.