Three-channel Measurement To The Ddc System And Data Transfer Interface Design

The basic functions of radio direction finding is to estimate and invert for the location of radio emissive source. In other words, radio direction finding is a process,which is to make use of the features that radio waves transmit along a straight line,then to determine the angle between a reference direction and the line, which connects radio emissive source for testing and observation point, by radio measuring equipment.As ones of the deep research points of each country in the world, Software Defined Radio's basic idea is to base on a common, standard and modular hardware platform, where the analog processing is reduced, the digital processing is as close to the antenna as possible and a variety of functions of radio stations and communication are realized through software programming.This paper gives a solutions and hardware architecture to the three-channel direction finding system. The data acquisition board and PC machines are the back-end, and they can be used as a common platform in direction finding system.. The design of data acquisition board is based on the idea of software-defined radio. It plays an important part in the acquisition of IF signal acquisition and processing. Virtex-5 FPGA is the center of the acquisition board. Its front-end is the A/D and DDC parts, the function of which is to digitize IF signal and convert it down to baseband digitally. The back-end of Virtex-5 is a PCI Express data transfer part, whose function is to send the processed data to PC. Both of these two parts are indispensable. Secondly, analysis and simulation of digital down conversion process during the DDC chip ISL5416 is provided and the its configuration is researched, also the implementation of data transfer through PCI Express interface is explained. Finally, the three-channel direction finding system is debugged in the background of using in the wideband correlation interferometer direction finding, also the summarization and prospect are given.The debugging results demonstrate that the IF signal acquisition and data transmission work normally in the system. The digital down conversion of IF signal can be realized and the mutual data transmission can meet the current needs of the system. The predicted design goal is achieved.