Research On Key Technologies For IF Multirate Receiver

With the rapid development of wireless communication technology, as well as a sharp increase in demand for large data transmission, wireless communication in various fields, especially in broadband satellite communication systems, high-speed data transmission brings many problems of multi-rate processing and synchronization. To solve these problems, this dissertation studies three aspects about it, which are the multi-rate IF receiver data processing, carrier and timing synchronization of digital demodulation.This dissertation combines with the project "The design of broadband satellite communication terminal modem" and designs the broadband satellite receiver system with the specifications of the design. The receiver is based on MPSK modulation and demodulation. By studying the timing synchronization, an improved Gardner timing synchronization algorithm is proposed, which can synchronize at a faster speed with sufficient synchronization accuracy. Combining the PF algorithm with PD improves the capture range and accuracy of the carrier synchronization algorithm. After the study of the basic structure of the multi-rate processing, use the sampling rate conversion based on polyphase filter to complete this task in the project specifications.This dissertation builds a system model and completes the analysis of system performance parameters such as bit error rate based on Matlab / Simulink platform, proving that the difference with the theoretical BER curves of the algorithms proposed is within 0.5dB and meet project requirements. Finally, write and verify the VHDL code of the system with the ISE and Modelsim; then complete the hardware debug of the subsystem based on Xilinx FPGA platform, verifying the feasibility of the system.