| 摘要: |
| 在卫星扩频通信系统中，通常采用自动增益控制(Automatic Gain Control,AGC)技
术解决大动态的信号起伏和干扰，以实现扩频信号的快速捕获和跟踪。分析了扩频接收机基
带信号数字采样门限，通过用信号包络功率值作为AGC控制信号，实现了接收基带信号大
动态范围的信号处理，完成了数字AGC自适应控制。利用扩频信号进行完全捕获后的包络信
号作为AGC信号可以有效防止信号捕获过程中多普勒频移等引起的失锁和误捕，实现
扩频接收机RF（射频）信号大动态范围的信号控制。 |
| 关键词: 卫星通信 扩频信号 数字自动增益控制 门限 |
| DOI： |
|
| 基金项目:国家重点基础研究发展计划（973计划）项目（2007CB815504） |
|
| Design and Implementation of Digital AGC Based on Baseband Signal Envelope |
| PEI Jun,HU Zheng-qun,DU Xiao-hui |
| (National Astronomical Observatory,Chinese Academy of Sciences, Beijing 100012,
China) |
| Abstract: |
| In satellite spreadspectrum communications systems, a
utomatic gain control（AGC）technique is commonly used to solve the large dynam
ic range against t
he signal fluctuating and interference. In this paper, the digital sampling thre
shold for spread spectrum signal is analyzed, as a result, the spread spectrum s
ignal power envelope is used to complete the digital AGC, and the signal power
envelope in the signal acquisition phase prevents from losing and mistaking sign
al acquisition caused by Doppler frequency shift and can realize adaptive RF rec
eiving signal control in large dynamic range. |
| Key words: satellite communication spread spectrum signal digital automatic gain control t
hreshold |
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