.¦Ð/4-dqpsk Modem Technology And Fpga Implementation

This paper study theπ/4-DQPSK modulation system based on FPGA. It realized the full digitalπ/4-DQPSK demodulation. The intermediate frequency is 10MHz, The bit rate arrives 10Mbps. It can be used to transmit image information between telemetry monitoring room.The main content include:π/4-DQPSK modulation, 1bit intermediate frequency differential detection simplified algorithm, Gardner bit synchronization algorithm. It Focuses on the principle of each module in the system, and the improvement in the farrow filter, complete each module design and FPGA realizing. Respectively, 1 bit differential detection and normal differential detection have been used to demodulate. The performances and the resource consumption of the implementations in FPGA have been compared between two algorithms. This paper finished the principle simulation of the system in matlab. It proved that it is feasible in principle. And I programmed in Verilog in ISE environment to achieve each module function, and make very module simulated and debugged in Modelsim, realized the demodulation ofπ/4-DQPSK and code element synchronization. And I completed the hardware realization and test of the system.