Research On Digital Beamforming Algorithm And Its Implementation Technique For Telemetry System

Digital beamforming is the product of combination of array antenna and digital signal processing technologies, it is a good solution to the conflict between antenna gain and coverage, and it is an important development trend of the future telemetry antenna technology. According to the performance of various digital beamforming algorithms and the characteristic of reentry telemetry, two shechems are proposed: switched beam system and DOA based adaptive beam system. The main work of the dissertation can be summaried as follows:1. The performance of MVDR beamforming with array errors is analyzed. A robust multistage wiener filter algorithm is proposed, which has low computation complexity and good robustness against steering vector mismatch and the number of truncating stages of multistage wiener filter.2. A constrained adaptive algorithm is developed for sum and difference beamforming. It is implemented in a general sidelobe canceller structure, a reduced-rank blocking matrix is adopted to reduce computation complexity, and an additional constraint condition is employed to control the distortion of monopulse ratio curve.3. All kinds of array errors are analyzed, mathematical models are established, and corresponding calibration methods are discussed. The influences of residual errors on beamforming performance are also analyzed, which can be used to aid in establishing torlerance budget for practical array design.4. Digital beamforming experimental system is designed, array antennas and RF front-end are tested,and array calibration,DOA estimation and monopulse tracking algorithms are experimentally verified.