Digital Beamforming And The Tracking Algorithm

Based on modern digital signal processing, digital beam forming is a new constructed technology which is widely used in radar, sonar, communication and electronic countermeasures zone. The digital beam forming algorithms, digital beam forming tracking technology to the moving targets (including single target and multiple targets) are studied further. The main research contents and results are as follows:1. Several classical digital beam forming algorithms are analyzed and compared their capabilities. A new MVDR algorithm which can improve the robustness of the algorithm is introduced in the case of angle estimation errors. It can form the beam in the direction of the desired signal and improve the SINR.A new beam forming algorithm based on circular array is proposed. Through using the special phase relationship of the arrays, this method can make the nulls more deep in the case of the limited snapshot number and low SNR .The simulation results show the validity and efficiency.2. The CMA blind tracking algorithms are introduced. The CMA algorithm can track the moving target without knowing the initial knowledge of the target. But it can't track the target if the power of interfere signal is stronger than the desired signal's power. There are three CMA algorithms: common CMA, LS-CMA, RLS-CMA are studied and use them in the research program, the simulations show that CMA1? 1 and CMA2 ? 2tracking algorithms can steadily achieve the effective searching and tracking of the moving target.3. Three non-blind targets tracking algorithms are introduced. The gradient tracking algorithm based on MMSE, the Sword tracking algorithm based on Kalman and the PASTd tracking algorithm based on signal subspace tracking. These algorithms need to know the initial angle information. The simulation results show the validity and efficiency.4. An improved multiple targets tracking algorithm based on circular array is proposed. The new algorithm can track the azimuth angles and the pitch angles of multiple targets. The simulation results show the validity and efficiency of the new algorithm. And at the same time, this algorithm is used in arbitrary arrays, and the simulation results show that there is enough space to improve it.