Study Of High Speed Transfers System

In the measuring-mine system of petroleum, the system of express remote transmission plays an important role. The system of express remote transmission is used to transmit a lot of data accurately in time at a high speed between instruments outside mines and instruments in mines, and therefore, the system is throat of the process of collecting data, transmitting data and controlling data in measuring mines. In order to meet the need of the fourth generation technique of measuring mine(snamely measuring mines'technique of image formation), a lot of information is required to upload. In the case, the old technique of transmitting data at a low speed can not meet present needs. Therefore, it is necessary to study express data transmission. According to the development and present status of the technology abroad and domestic, a design plan is put forward based on the DSK of TMS320C6713B made in Spectrum Digital corporation and QAM modulate and demodulate algorithm.In the design of algorithm, several algorithms of modulation and demodulation are compared with each other, and QAM is selected to finish to the system according to the system requests and the complexity extent of algorithm realization. Before designing high speed transmitter system, the modulation process and demodulation process of QAM is simulated by matlab.Then, C language and assembly language is used to design several programs such as QAM program, CRC verification program, control programs of DSP and MCU and so on. In addition, block diagram are used to realize the logic control program of CPLD.In the design of system hardware, TMS320C6713BDSK development board made in the company of Spectrum Digital is selected as a main board of developing the system. Then select type of single chip,FIFO,A/D,D/A,and CPLD chip according to system requriement. In addition, CPLD, singlechip, FIFO, A/D and D/A are used to from ground instrument interface circuit of HMI and cable transmission interface circuit.By the experiment, the system can upload data and download commands with low errorrate and the transmission speed of system is 80kbps. It is turned out that the design of QAM can meet the requests and the transmission efficiency can be promoted efficiently.