Quasi-equal-phase beam compositing algorithm in multi-beam satellite systems

In multi-beam satellite systems, users suffer from 3dB power attenuation in beam-edge area. Joint transceiving can be used to improve this situation. It requires signals of several beams (downlink) or several users (uplink) to be equal-phase, which needs channel estimation and seems to be complex. The purpose of this paper is to reduce complexity of joint transceiving by compositing quasi-equal-phase beams. Firstly, radiation pattern of original component beams are discussed and calculated. Then a modified Least Mean Square (LMS) algorithm is presented to composite quasi-equal-phase beams from component beams calculated above. Lastly a numerical calculation is presented to show that quasi-equal-phase beams are composited with phase error smaller than 0.32 radian.