1 Introduction That a laser beam is scattered from rough surfaces attracts many researchers. In1987, E. R. Mendez and K. A. O’Donnell first observed the enhanced backscatteringthat a laser beam (6328 A) was scattered...1 Introduction That a laser beam is scattered from rough surfaces attracts many researchers. In1987, E. R. Mendez and K. A. O’Donnell first observed the enhanced backscatteringthat a laser beam (6328 A) was scattered from a metal rough surface, whose most impor-tant feature is the high rms slope of the profile. Kirchhoff single scattering modeland small perturbation theory cannot be used to get this effect theoretically. Howev-展开更多
To reduce the side-lobe level of L-shaped expansion array and improve the output signal to interference and noise ratio(SINR),the algorithm of side-lobe constraint based on minimum variance distortionless response(MVD...To reduce the side-lobe level of L-shaped expansion array and improve the output signal to interference and noise ratio(SINR),the algorithm of side-lobe constraint based on minimum variance distortionless response(MVDR-SC)is proposed.Firstly,the approach of mixing diagonal loading and Mailloux-Zatman(DLMZ)is used to taper the covariance matrix of the expansion array.Then,the second order cone programming(SOCP)obtained by constructing a new matrix is used to control the beam side-lobe.Finally,the new adaptive weight numbers are constructed by adjusting the proportion between DLMZ and SOCP.Simulation results show that the MVDR-SC algorithm can effectively reduce the side-lobe of beamforming under the L-shaped expansion array and obtain a larger output SINR.At the same time,it has good robustness to the mutual coupling error.展开更多
文摘1 Introduction That a laser beam is scattered from rough surfaces attracts many researchers. In1987, E. R. Mendez and K. A. O’Donnell first observed the enhanced backscatteringthat a laser beam (6328 A) was scattered from a metal rough surface, whose most impor-tant feature is the high rms slope of the profile. Kirchhoff single scattering modeland small perturbation theory cannot be used to get this effect theoretically. Howev-
文摘To reduce the side-lobe level of L-shaped expansion array and improve the output signal to interference and noise ratio(SINR),the algorithm of side-lobe constraint based on minimum variance distortionless response(MVDR-SC)is proposed.Firstly,the approach of mixing diagonal loading and Mailloux-Zatman(DLMZ)is used to taper the covariance matrix of the expansion array.Then,the second order cone programming(SOCP)obtained by constructing a new matrix is used to control the beam side-lobe.Finally,the new adaptive weight numbers are constructed by adjusting the proportion between DLMZ and SOCP.Simulation results show that the MVDR-SC algorithm can effectively reduce the side-lobe of beamforming under the L-shaped expansion array and obtain a larger output SINR.At the same time,it has good robustness to the mutual coupling error.
