A Digital Receiver Module Of The Software Design

In the system of radar or communication, signal receiving is absolutely necessary. With the development of technology of modern communication, micro-electronics and computer, radio-communication is working with more and more digital and software system. Thus Software Wireless appears. It is based on the system of data sampling and processing with high speed and high precision. For these reasons, the study of the software design for digital intermediate frequency receiving-module, which is based on the bus of CPCI, is performed.Analog signal becomes discrete directly in intermediate frequency after it passing digital intermediate frequency receiving-module. Then the discrete signal is processed with DDC (Digital Down Converter), filtering, decimating and demodulating until the useful signal is acquired.Considering the designed digital intermediate receiving-module's special application, CPCI bus is chosen for data transferring. The bus has many characteristics which can meet the special needs, such as mechanical module with Industry Standard Architecture, good linking, compatibility and transferring data with high speed.There are two important parts in this paper.1. Driver design for digital intermediate frequency receiving-moduleFirstly, the paper introduces the kernel of operating system, the characteristics and the key technology of developing of WDM. Secondly, it provides the main functions and the methods of using PCI 9054.Thirdly, the developing and debugging tools are chosen. Finally, it puts emphases on analyzing and implementing WDM driver, which includes producing driver frame, designing key function modules and debugging with hardware.2. Application software design for digital intermediate frequency receiving-module Considering its practical application,the paper introduces the application software design of digital intermediate frequency receiving-module from the aspect of intermediate frequency receiver. The designed software can demodulate the received ASK+DPSK signal. It provides the arithmetic and realization of carrier recovering. Also, it offers the type of filter and a recommended value for cut-off frequency choosing for filtering zero intermediate frequency baseband. At the end of the paper, it presents a method of picking-up bit synchronization signal and gets the original bit stream.