| A new digital beamforming algorithm for small satellite system is proposed in this paper. First the introduction of satellite antenna and array antenna is introduced. Then the smart antenna is disscussed, including the principle, the characteristics, the classification and some commonly used algorithms. The next part is about the characteristics of receiving beamforming, transmission beamforming , multi-beamforming and the principles and criteria of digital beamforming. After that, the simulation and analysis of traditional beamforming algorithms is given. Combined with the study of adaptive beamforming, adaptive sidelobe canceller and the space-time signal processing technique, a new digital beamforming referred to as two-domain time filter with space adaptive signal processing is proposed. It consists of two cascaded digital beamformings: the first is referred to as spatially interpolated beamforming; the second is referred to as the adaptive cancellation technology based on uniform circular array. Since the small satellite is not equipped with solar piracy, the array elements should be laid on its surface. Meanwhile, due to its stealth ability and small size, the number of array elements is strictly limited and the reduction of the computational load is necessarily required. A 2×2 plarnar array is employed in simulation. The results show that compared with the traditional beamforming methods, the new methods presented in this paper is easy to realize. It has been proved that the number of the array elements in the new algorithm is much smaller than that in the traditional one. Thus, the new method requires fewer elements to achieve the same performance as the other methods. It reduces the computational load significantly, with respect to the number of antenna elements as well as the reciver modules and A/D converters. Furthermore, the new proposed method allows specifying narrow main beamwidth and low sidelobe level simultaneously. |
PDF Full Text Request