Qpsk Modem And The Design And Realization Of The Image And Data Transmission System

The content of the paper is the research and develop projects of the corporation, which include QPSK modulator and demodulator design and its practical application(e.g. To be applied in digital television transmission,Ethernet fixed wireless access system,DVB data broadcast and far distance data communication for EIA RS232C,etc).Digital signal transmission technology(the pulse shaped technology, line interface code HDB3 in digital base-band transmission; QPSK modulating and demodulating principle in digital carrier transmission), error control technology in digital communication are presented in this paper. The sameness and difference between FPGA and CPLD are also discussed. The structure and usage of FPGA, the usage of EDA design software and design flow are introduced in the paper as well. With these communication theory and engineering technology guidance, the author has fulfilled the software and hardware design and debugging of QPSK digital communication system. Finally the QPSK digital communication system was applied in the digital television transmission,the fixed wireless access between two Ethernet and the far distance data communication with EIA RS232C.The works which the author has done are as follows:To have accomplished QPSK modulator and demodulator hardware design with ASIC and other auxillary components.To have designed convolutional interweaver and deinterweaver according to DVB criteria for MPEG-2 transport stream.To have made HDB3 encoder and decoder as E1 interface.To have accomplished the wireless connection between two Ethernet with E1 to 10BASE-T interface circuit.To have accomplished the far distance data communication for EIA RS-232C.