基于扩频处理器的通信系统的实现

本文设计用扩频处理器实现了报警系统的数字扩频。上电复位后，芯片处于接收状态，
工作在突发模式下，采用DPSK 调制方式，将AD9057 转换完的中频信号进行复正交取样后下变频、解扩、解调，通过中断将解调完的基带信号送入单片机处理;处于发送状态时，可将数据扩频、调制，经AD9768 送出。通过对其内部87 个寄存器写入数据可对其进行控制。实现了扩频通信系统的数字信号处理。
关键字: 扩频通信系统；报警系统；DPSK；
Abstract: This paper designs the twice civil air defense alarm system's digital spread spectrum
communication with STEL-2000A. When the circuit resets, the chip remains accepting state, works in burst mode, and adopts DPSK modulation mode. It precedes quadrate-sampled intermediate frequency signal after the AD9057 has converted, then down-converses, dispreads and demodulates. The demodulated baseband signal will be sent into SCM to dispose through interrupt. If the chip remains sending state, it will take the data spread spectrum and modulate, then sent forth by AD9768.The chip can be controlled through writing data in the interior 87 registers.
Keywords: Spread Spectrum Communication System; Alarming System; DPSK