Adsl Data Acquisition And Analysis System

This paper is based on DMT(OFDM) transmission theory, mainly discussing the design principles and methods about real time data collection system based on ADSL.First, this paper makes an intensive study of OFDM technology and ADSL network. In this paper the QAM, CAP and DMT technology are analysed. The ADSL system model based on twisted pair is discussed, and researches in system synchronization characteristic are laid out.Second, holistic design scheme of the system is pointed out, mainly focusing on signal accessing circuit, the cell dealing with module, UTOPIA interface and CTRL-E interface controller and etc. At the same time the state conversion of simulation ADSL module, system initialization, data encapsulation, the cell demarcation and valorize velocity matching are expounded.The method of modularizing design is adopted in the actual realization and some exclusive chips are specially used in every block. So it endows the system with high integrity. Interface data acquisition, upward and downward data link channel, USB controller, interface controller etc are realized by VHDL.Many technology is synthetically adopted, such as, DMT technology, ADSL network technology and design technology based on FPGA hardware etc. This system can be used real time dynamic test for twisted-pair network, The system is integrity in its structure, and works reliably and steadily, satisfying the request and the target well.