| 摘要 |
<p>An RF circuit switch system having particular use in an antenna diversity scheme for a CDPD system relies upon a comparison between current signal values on a selected antenna and a predetermined value based upon previous signal values measured on the same antenna. This comparison determines whether switching will occur from one antenna to another. Normally, the predetermined value will be adjusted based upon present signal strength on the selected antenna. Switching is normally attempted when there is a drop of approximately 10 dB in the signal strength of the selected antenna. If the signal strength in the other antenna is found to be less than that of the original antenna upon switching, an automatic switch back is carried out.</p> |
