If Digital Processing

In this paper, we discuss the basic principle of the modernity communication and the spread-spectrum communication, discuss the principle of IF digital correlative processing and the realizing method. At present, the equipment with complex function is gradually replaced by digital circuit design. The function with analogue in the complicated design is delayed out little by little. In generally, the means of analogue is only applied to the limited design, such as weak-signal amplified high-speed sampling and high-power outputting; but the other design with digitize. In the wake of developments in VLSI and ASIC, the analogue circuit is slowly replaced by digital circuit. The purpose of this paper is that taking use of modern digital technical apply at correlative processing in the IF signal of spread-spectrum system. In this paper, we detail the principle of the matched filter and the signal sampling, introduce how to process the IF signal by ASIC, and introduce the ASIC's function and constitution. We supply detailed principle diagram and circuit diagram in the paper. The method of IF digital correlative processing that is the basic of digitize of receiver's channel.