Research Of Adaptive Beamforming And Hardware System Technique

Digital signal Processing technologies were used to Produe spatial and diretional beam in smart antennas.The main beam aims at the coming diretion of refernce user and the side lobe points to the coming diretion of inteerfrenee user.Smart antennas are classified to switching-beam and tracking-beam.Smart anatenna technology has been confirmed as one of key technologies of the third generation mobil communication system,and will play an important role in the future.First of all some kinds of beamforming algorithms are introdueed,including non-blindalgorithms and blind algorithms,and their performance is analyzed and compared with each other. Then the theory of diagonal loading is introduced and the way how to choose the value of diagonal loading is put forward. The method used in this paper can adjust the value adaptively according to the sampling data,and has excelent performance.Then based on the problems of the constant modulus algorithms capturing the interference signals and the preprocessing algorithm applied in corruptive environment,a widely used constant modulus algorithm based on minimal Rayleigh entropy is proposed.The simulation results indicate their effectiveness.Secondly, The author design system with DSP and FPGA based on the LMS algorithm of adaptive beamforming.Then introduce the software design of the algorithm based on C3X assembler language,the programming of FLASH and bootloader design of the DSP system.