A Research On The Key Technology Of The Direction Of Arrival Detection And Receiving System

The detection technology of the direction of arrival(DOA)has been playing a more and more important role in recent years,with the development of wireless and mobile communication technology.As one of the main technologies of smart antennas technology,Its fundamental principle is to use phased array in both receiving and transmitting,achieving the communication in different directions of different users through narrow beam.In this way,we can improve the sensitivity of reception and efficiency of communication,decrease the multiple access interference and increase the capacity of the communication system.Although the way of array receiving and transmitting increases the array elements and components used,these costs are relatively small and acceptable to its advantages.As the core technology of smart antenna technology,the accuracy and resolution of DOA detection directly affect the efficiency of smart antenna technology in practical application.Smart antenna systems are generally divided into analog,digital and hybrid systems.In view of the technology,the fundamental principle of DOA detection is been learnt and studied in depth in this thesis and a set of hybrid experimental platform for DOA detection is designed,which means the combination of analog and digital,hardware and software,and in this way,the accuracy of DOA detection can be improved to meet the high precision positioning requirements of the fifth generation mobile communication 3D MIMO system and improve the system capacity.The platform is divided into 2 main functional modules: DOA detection and beamforming,both using 8 channel,working in the 5.8GHz band and,fusion location and transceiverfunction,is designed to apply to 5G system for communication location.The main contents of the work are as follows:1.The array receiving,especially the principle of smart antenna technology,is learned and studied in depth.According to its technical characteristics,the relationship between phase precision of phase shifter and DOA detection performance is analyzed.An analysis of the principle of beam-forming and influence factor of its performance is done and relevant conclusions are given.2.According to the principle of DOA detection and beam-forming,the hardware system scheme of receiver and beam-former is designed,followed by simulation and analysis of effectiveness and feasibility to make the scheme improved.3.According to the proposed scheme,the appropriate devices are selected and also the scheme is adjusted slightly according to existing components,ensuring the feasibility of the initial plan,and getting the final plan after repeated adjustment.Finally,the circuit diagram and PCB layout are implemented and machined.4.Finally,the hardware debugging and testing of each module are carried out to ensure that each module can work properly,and then the whole system is tested jointly to verify the performance of the system.