本文設(shè)計用擴(kuò)頻處理器實現(xiàn)了報警系統(tǒng)的數(shù)字?jǐn)U頻。上電復(fù)位后，芯片處于接收狀態(tài)，
工作在突發(fā)模式下，采用DPSK 調(diào)制方式，將AD9057 轉(zhuǎn)換完的中頻信號進(jìn)行復(fù)正交取樣后下變頻、解擴(kuò)、解調(diào)，通過中斷將解調(diào)完的基帶信號送入單片機處理;處于發(fā)送狀態(tài)時，可將數(shù)據(jù)擴(kuò)頻、調(diào)制，經(jīng)AD9768 送出。通過對其內(nèi)部87 個寄存器寫入數(shù)據(jù)可對其進(jìn)行控制。實現(xiàn)了擴(kuò)頻通信系統(tǒng)的數(shù)字信號處理。
關(guān)鍵字: 擴(kuò)頻通信系統(tǒng)；報警系統(tǒng)；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