The method of beam-forming for SA in line array by amplitude weighting

QPSK base-band amplitude weighting (AW) is an effective method for smart antenna (SA) in line array to realize multi-user and multi-direction transmission. However, none of relevant materials has given out its principle or implementation scheme. According to the direction vector of SA and its principle of downlink beam-forming, this paper presents the basic principle and specific implementation scheme of this AW method, and then proves its correctness through simulation. Compared with carrier phase-shifting, the implementation scheme of beam-forming by AW has the feature of easy to implement and high reliability, so that the popularization and application of SA is possible.