The Design And Realization Of Pre-multiple Beam Switch Intelligence Aerial System

With the development of the social informatization, the need for the wireless telecommunication and data transmission of every field is increasing. As a brand-new wireless sense network technology which emerges as the times require, the standard of the ZigBee agreement has aroused the attentions of vast science & teleology workers domestic and abroad. The technology with the characteristics of tiny consuming energy, high ability of organizing network, low operation cost, high reliability can conveniently organize wireless lan local area network of low power consuming, short distance of data transmission and low velocity, which can widely apply to the fields of ingenious network telecommunication, industry automatic control, automatic charge and toll of the water& electricity & gas and wireless connection set by PC.On the other hand, the development of the mobile telecommunication accelerates the needs for the wire system. Intelligence wire can automatically change its map of the radiation directions with the change of the signal environment, which can improve the capacity, the quality and the coverage of the system. As a key technology of 3G mobile telecommunication, the intelligence technology has been paid more attention. The series problems of the inadequate telecommunication capacity, the declined telecommunication quality resulted by the rapid increase of the mobile users need to be solved quickly. Therefore, it is urgent to search for a new technology which can improve the capacity of the system and the quality of the telecommunication. As for the second generation of the mobile telecommunication system GSM, the phenomenon of the difficult supply for the capacity has appeared in the large cities in China. The radius of the district honeycomb is quite small already and as the key point of the application survey, 3G and vocation ability will definitely exerts higher requirements on the network capacity. The high-speed data service, as the main characteristic of 3G network service, obviously increases the flow of the network data especially the descending direction. Therefore, to realize the service in the system of 3G which is different from the second generation system obviously and to embody the advantages of the 3G system in the aspect of vocational capability, network capacity is the key problem that the network operators must consider.As for the current condition, intelligence wire technology will be one of the most effective ways to increase the network capacity, especially for the telecommunication system in 3G whose main interference form is the self-interference. It utilizes the dynamic state of the numeral signals disposal technology to produce wave packet to make the main wave packet of the wire to follow the tracks of incoming wave direction of the expected user signals and the sidelobe or to aim at the incoming wave direction of the interference signals in the zero defect way to effectively utilize the mobile user signal and to delete or restrain the interference signals.Intelligence wire is a kind of bi-directional wire which is installed in the spot of the base station. It can get the direction traits by a suit of fixed wires that can program phase position relation of the electron. It also can get the direction traits of the link circuit between the base station and the mobile station. Intelligence wire technology, utilizing the difference of the signal space traits among the mobile users , receive and emit multiple mobile user signals on the same information channel without the mutual interference by the array wire technology, to validate the usage of the wireless electronic frequency spectrum and the transmission of the signals . On the condition that there is no more system complexity, the usage of the Intelligence wire can meet the needs of the service quality and the dilatation of the network.As for the application of the ZigBee agreement to the Intelligence wire system, there are a lot of scholars doing the research of the field currently. However, there is not a systemic conclusion of the analysis application of the interface of every layer of the ZigBee agreement, which brings inconvenience to the application exploiters who begin to set foot in the wireless telecommunication flushbonading system such as the Intelligence wire system.The article introduces a hardware architecture scheme of the intelligence wire system, the application of the agreement and the monitor algorithm of the direction of the incoming wave. By consulting a large number of materials domestic and abroad, It does deep study on the IEEE802.15.4 standard and the ZigBee agreement. It also crack and read the apache code of the ZigBee. It introduces the exploitation theory and the interface realization of the ZigBee agreement in detail and analyses the realization course of a demo program of the ZigBee in detail. It also does a thorough research on the assessment algorithm of the direction of the incoming wave, and realizes it by the maximum likelihood method.The system is made up of the source of the mobile signals and the base station. The base station is composed of the wire array, wave celerity formation network, wave celerity control cell, receive cell, emission cell and baseband handle cell. Among them, baseband handle cell uses ARM chip, self-adaptation handle cell adopts FPGA chip. This is because that it requires higher algorithm rate in the period of wave celerity formation, wave celerity switch, so it uses specialized FPGA chip to handle it independently.In the course of the application exploitation of the ZigBee agreement, it develops the agreement based on the multiple hardware platform, including microchip, win32 etc. In the course of the application exploitation, the system adopts the application exploitation based on win32.It includes the exploitation of the hardware drive array, ZigBee agreement array and the user application array. The hardware drive array is responsible for the RE module allocation. The salient point is that Radio Channel, development board button and development board LED manage the sharing internal storage space analogously by the allocation; the ZigBee agreement array is mainly to realize the normal operation of the ZigBee agreement; the user application array realize its specific application based on the ZigBee agreement.In the intelligence wire system, the detection algorithm of the direction of the incoming wave is the core of the wave packet formation, which determines the capability of the whole wire system and the conversation quality of the user termination. Therefore, it is very important to choose a algorithm to detect the direction of the incoming wave. To extract the information of the direction of the incoming wave is one of the key tasks of the intelligence wire system, especially the several key parts of the Pre-multiple beam switch intelligence aerial system. There are many parameter assessment algorithms about it. Wave packet scanning method based on Fourier analysis is the classic method of the analysis of the direction of the incoming wave, but the increase of the aperture is influenced by the various actual parameters. R.O.Schmidt raised MUSIC method in1980s. The method introduces the aspect of linearity space into the assessment of the direction of the incoming wave, and divides the linearity space into signal subspace whose vector is guided by the signals and its orthogonal subspace–the noise sunspace Then, it gets the assessment of the signals subspace by decomposing the assessed traits of the covariance moment array and searches for the signals directions by using the vector guided by the parameter to drop shadow to the noise sunspace. In 1988, L.Ziskind and M.Wax applied the Maximum Likelihood method(ML) which is very classic in the assessment theories to the DOA assessment; in 1991, M.Viberg raised Weighting Sunspace Fitting method (WSF), whose traits lie in setting a frame including lots of super-resolution methods ,such as multi-dimensions MUSIC, the Maximum Likelihood method, subspace circum gyration immovability method(ESPRIT) etc. The article realizes the detection of the direction of the incoming wave by the Maximum Likelihood method based on the two classic detection algorithms of the direction of the incoming wave--MUSIC algorithm and ESPRIT algorithm.The design and realization of the intelligence wire system still need improvement, which is dependent on the deeper research in days to come.