Qpsk Demodulator Based On The Pxi Bus Module Design

This paper gives the designing method of a PXI bus-based QPSK demodulation module based on the research of the PXI bus specification.The whole digital QPSK demodulation module scheme adopted the advanced DSP controlling. It also applied the newest software defined radio technologies such as analog-to-digital convert at intermediate frequency, digital down converter, integrate and dump filter and carrier synchronization, symbol synchronization in digital demodulation and so on. The distinguish characteristics of this scheme are the combination of software and hardware, simple computational complexity of system and it can be easily implemented by DSP.Besides, the system-level PXI specification which is apt to integrate and use was adopted. PXI supplies firm industrial encapsulation, more instruments module extension slot and advanced capabilities of trigger, timing and side-band communication. The notable features of PXI benefit the modularization of QPSK demodulation system. Similarly, it pushes the integration of testing systems ahead which blong to different manufactures. The automation platform based on the opening and multiple manufactures' standard satisfied the requirement of testing and measurement in communication system.This paper accomplished the following parts of work:(1) Studying and demonstrating of the whole digital QPSK demodulation method and materializing of the system on high-speed DSP.(2) Designing of the hardware of PXI interface adopted the scheme which is using PCI 9054 combined with CPLD after comparison.(3) Researching on the designing method of driver and front panel of PXI devices.