Study On Adaptive Digital Beamforming Based On Direction Of Arrival Estimation In Multi-vehicle TT&C

The tracking, telemetry and command (TT&C) system of aeronautics and astronautics in our country has stepped into the second generation with more than 50 years'development, e.g. unified carrier TT&C system. Now, our TT&C network consists of TT&C land-based and sea-based stations. In this network, one TT&C station can only deal with one vehicle and it can't track the vehicle on all over the earth. With the development of aeronautics and astronautics technology and demand of national defence, it becomes more and more necessary to realize the multi-vehicles TT&C. One typical application is the TDRSS. In order to track the vehicle during the whole flying process, we can move the TT&C station up in the space, which is just the TDRS. Since it is impossible for one TDRS only to track one vehicle, multi-vehicles TT&C is required. Another application is the microsatellites. Usually, there we will use many microsatellites at the same time in the space due to the low cost of satellite. The multi-vehicles TT&C can decrease the cost significently. Even in the traditional TT&C network, multi-vehicles TT&C is an important approach to update and regenerate old equipments.The implementation of multi-vehicles TT&C mainly depends on adaptive DBF technology. Adaptive DBF steers the main beam face towards the desired signal and suppresses the interferences at the same time through the spatial filtering according to the signals'DOA. It only needs one set of hardware to work out a few weight vectors by software, obviously one weight vector forms one main beam. Adaptive DBF consists of wireless communication technology, but the key is the baseband digital signal processing. The performances of the system are analyzed in special conditions, which is important for the hardware design. The author improved the beamspace adaptive DBF algorithm and DOA estimation algorithm, anymore designed and built the hardware for the modulator, demodulator and baseband circuit.The main works conclude that(1) In the model of ULA, the main parameters of the DBF system are introduced first. We then derive the optimum weight vectors with different optimum criterions. But all of them are Wiener solution. Through the simulation of MVDR beamformer, we can know the function of the spatial filter to the communication receiver.(2) The relationship between system and number of bit, so as the system and number of snapshots and array mismatch are present. The relationship between system...