Research On Anti-Jamming Method Of Millimeter Wave MIMO

Millimeter-wave(mm Wave)has become a popular topic recently due to its high frequency band and short wavelength,as well as its rich spectrum resources.Combined with massive multiple-input multiple-output(MIMO),the base stations(BS)can be integrated with more antennas,which can improve the system transmission rate to meet the ever-increasing user demands.To suppress interference,the mm Wave precoding matrix is designed to align with the beam in the desired direction.However,the traditional anti-jamming method is ineffective in suppressing the highly directional artificial interference in mm Wave massive MIMO systems.Therefore,thesis investigates the method of detecting and suppressing strong artificial interference in mm Wave MIMO systems.The first step to suppress jamming in a mm Wave massive MIMO system is to correctly determine the presence and location of jamming.Considering that the traditional jamming detection and suppression methods are highly targeted,thesis adopts the linear zero-forcing jamming suppression(ZFJS)based method to jointly design the receiver with the user estimated channel and the jamming estimated channel with single user and single jamming model.Moreover,for the multi-user multi-jamming model,thesis proposes a hybrid-array-based jamming detection and suppression method with spatially discrete angular-domain sparse channels in mm Wave massive MIMO system.Due to the channel sparsity,the direction and strength of the jamming signal and the user signal can be estimated with the compressed sensing theory,and the jamming signal in the analog domain can be estimated with channel state information of the user and the jamming.Numerical simulations evaluates the performance of the proposed jammer detection method in terms of correct detection probability and false alarm probability,with significant effectiveness when the jamming power is much lower than the user power.Most of the existing anti-jamming techniques assume that the interfering signals are uncorrelated with each other.However,when the interfering signals are highly correlated,especially when the correlation coefficient varies,the suppression of the interfering signals is more challenging.Considering that the traditional anti-jamming technology is ineffective when the correlation of the jamming signal varies,analyzes the influence of the non-zero invariant and non-zero varying correlation between the jamming signals on the jamming signal suppression on the basis of detecting the existence of the jamming signal.The jamming suppression matrix is updated in real time by tracking the zero-space variation of the jamming signal.Only a spatial data stream at the transmitter is used in the proposed jamming cancellation method to suppress the jamming signal,ensuring that the remaining streams can communicate efficiently with legitimate users.The simulation results show that the method can effectively eliminate the jamming signals under different correlation values.