A DBF self-beam steering array antenna for mobile satelliteapplications using beam-space maximal-ratio combination

摘要

This paper proposes a diversity-receiving array antenna schemenachieved by digital beamforming (DBF) for the purpose of self-beamnsteering toward the unknown direction-of-arrival (DOA) of a modulatednsignal in a mobile satellite communications environment. This schemenuses a multibeam former with a spatial fast Fourier transform (FFT) fornthe received baseband signals to coarsely acquire the attenuated signal.nIt also uses a self-phasing processor (SPP) applied to the multibeamnoutputs for precise acquisition and tracking. In the SPP, maximal-rationcombining is achieved with simple digital numerical operations in thencomplex baseband, allowing for rapidity and stability in beamforming. Asna result, the array antenna steers its receiving beam toward the DOAnautomatically without the need for nonlinear optimization methods.nMoreover, the beam is steered toward the DOA of multipath signalsnaccording to their signal levels, leading to the optimal cophasenrecombination of all correlated signals, which improves the quality ofnthe total receiving signal. This paper discusses the scheme, and itsnperformance is evaluated by computational simulation and experimentsnconducted in a radio anechoic chamber