| 摘要: |
| 卫星通信中，接收机经常要在较大频偏下实现对M-PSK信号的载
波同步；频偏较大的条件下，使用锁相环对信号进行载波同步需要较长的捕获时间，而且如
果频偏超出锁相环捕获范围，将无法实现捕获。基于传统的相频检测器，提出了一种改进方
案，通过增加相频检测器的“保持”区间，增大了频偏较大时相频检测器输出的直流分量，
从而可以更快地实现对频偏的捕获。仿真结果表明，该方案可以帮助锁相环实现更大的频偏
捕获范围和更快的捕获速度。 |
| 关键词: 卫星通信 大频偏；M-PSK；载波同步；相频检测器；捕获 |
| DOI： |
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| 基金项目: |
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| Fast carrier synchronization of M-PSK signals under large frequency offset |
| XU Feng,QIU Le-de,WANG Yu |
| () |
| Abstract: |
| In satellite communications, digital receivers often need to achieve carrier syn
chronization under large residual frequency offset. Under large frequency offset
s, long acquisition time is needed when using phase-lock loop(PLL) for carrier
synchronization,and acquisition will fail if frequency offset is beyond the acqu
isition range of PLL. Based on conventional phase-frequency detector (PFD), an
improved solution is proposed, which can aid PLLs to gain a wider acquisition ra
nge and fast acquisition speed. The main idea is to prolong the “hold” range f
or of PFD, so that a greater direct current (DC) will occur when frequency offse
t is large. The improved solution is verified by simulation results. |
| Key words: satellite communication large frequency offset M-PSK carrier synchronization PFD acquisition |
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