Research On The Adaptive Beamforming Algorithms Of Smart Antenna

Digital signal processing technologies were used to produce spatial and directional beam in smart antennas.The main beam aims at the coming direction of reference user and the side lobe points to the coming direction of interference user.Smart antennas are classified to switching-beam and tracking-beam.Smart antenna technology has been confirmed as one of key technologies of the third generation mobile communication system,and will play an important role in the future.The author's main research work is focused on adaptive beamforming algorithms.Given a mobile channel model,the performance of several adaptive algorithms for smart antenna uplink beamforming are analyzed and a improved semi-blind least square constant modulus algorithm(SBLSCMA) is proposed.This algorithm is based on constant modulus algorithm(CMA).The computer simulation results indicate that this algorithm has several adavantages such as fast convergence,robusteness and suppression of the interference.Moreover,the author analyzes several multi-user separation algorithms for CDMA system and proposes a improved the least square despread respread multi-target constant modulus algorithm(LS-DRMTCMA), gives the computer simulation results as well,in order to make preparation for the third generation mobile communication.