Research On Location Algorithm Based On Smart Atenna

With the development of smart antenna theory and array signal processing technology,the research and application of location technology based on smart atenna are more and more extensive.There are extremely important meanings in radar direction detection, navigation, guidance and mobile telecommunication area.Digital signal processing technologies were used to produce spatial and directional beam in smart antennas.The main beam aims at the coming direction of reference user and the side lobe points to the coming direction of interference user.Compared with other technologies,smart atenna has a wide development prospect with its outstanding advantage in the application of location system.In this paper it is described that the technology of smart antenna,including its basic theory,basic concept, classification and the development trend of the research on this technology, and the key technology of location based on smart antenna is studied deeply.It introduces the domain requirement,wireless location algorithms and problems faced on present location technology. According to single station, direction finding and ranging as a joint positioning thought and the combination of TOA and DOA as the location method are used to design the location platform based on smart antenna,so that it can locate several targets at the same time.On one hand,the direction of the target is fixed by DOA method;on the other hand,the ranging project with time as the key parameter is designed, and the signal processing model is given.It is analyzed that the performance of ranging in conditions of different number of sources. According to single source, different beamforming algorithms are compared with each other.The computer simulation results indicate the effective performance of extracting desired signal.In the condition of multi-target sources, a novel multi-signals LS-CMA algorithm is proposed to solve the problem that several signals may converge the same signal in some traditional algorithms.This algorithm can not only seprate all these signals effectively,but also prevent these signals interfering each other when they are received at the same time.It has several advantages such as fast convergence and robustness,so it can improve the performance of the system effectively,and also have good practicality. The computer simulations results indicate that the ranging algorithm presented based on beamforming provides theoretical foundation for the location platform and has certain theoretical value.The design scheme of the platform presented by this paper based on smart antenna uses the combination thought of software radio and smart antenna,and IF pass band sampling digital structure to design all the modules of the hardware system of the location platform.This scheme can locate the target in long distance,and has relatively high positioning accuracy and steady performance,so that there are certain practical significance and reference value on engineering realization.