本文設計用擴頻處理器實現了報警系統的數字擴頻。上電復位后，芯片處于接收狀態，
工作在突發模式下，采用DPSK 調制方式，將AD9057 轉換完的中頻信號進行復正交取樣后下變頻、解擴、解調，通過中斷將解調完的基帶信號送入單片機處理;處于發送狀態時，可將數據擴頻、調制，經AD9768 送出。通過對其內部87 個寄存器寫入數據可對其進行控制。實現了擴頻通信系統的數字信號處理。
關鍵字: 擴頻通信系統；報警系統；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