| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To maintain the pull-in state of a Costas loop as long as possible even when the radio waves from the caught satellite become weak after the pulling-in has finished as well as making pull-in easily from a wide frequency range. <P>SOLUTION: A GPS receiver controls such that at the time of acquiring synchronization, a loop gain is made high, and a oscillation frequency range of NCO of the Costas loop is widened, and in retaining the synchronization, when the loop gain is low, the frequency range of NCO of the Costas loop is narrowed. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
