全数字扩频收发信机技术

An All Digital Spread-Spectrum Transceiver

  • 摘要: 提出一种在接收信号具有显著多普勒频移的不确定性条件下,适用于全数字实现的扩频码和载波快速同步的新型扩频收发信机技术.对伪码捕获采用了16个通道并行搜索伪码相位的方式,将原来单路捕获所需的时间缩短到1/16.AFC技术采用FFT校频的方式对载波残差进行对消,有效地消除了多普勒频差对解扩增益的影响.同时还采用了巴克码作为交织帧的帧头,在Viterbi译码时可以快速地进行节点同步,防止出现比特位模糊.该接收机能在极短时间内快速建立同步,有效地实现实时突发通信.

     

    Abstract: A novel all digital and practical spread-spectrum transceiver used in obvious Doppler shift conditions is presented. 16 parallel channels are used to acquire the PN sequence simultaneously, reducing the acquisition time to 1/16 of that in the single channel mode. The Doppler effect on the processing gain is eliminated with the FFT algorithm. Node synchronization in Viterbi decoding is achieved rapidly using the Barker sequence as the head of interleaving frame. Fast-synchronization in PN code and the carrier is thereby achieved.

     

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