I don't understand well why the performance of a multiplex receiver is still higher than a continous receiver? In literature they told someting about the integration of the spectrum of more sattelites but i don't understand it very well..
Early GPS receivers had a single signal processing channel that was switched (multiplexed) between the various satellites the receiver was using to compute a fix. If a satellite went out of view momentarily when the receiver was trying to get data from it, the receiver could lose the fix, and take some time re-acquiring satellites.
Current receivers have multiple processing channels (often 12), so they can process data from multiple satellites simultaneously, and will usually have data from more satellites than are really needed to compute a fix. This makes the fix more accurate, and tolerant of loss of signal from one or two satellites.
Peter Bennett VE7CEI
GPS and NMEA info and programs: http://vancouver-webpages.com/peter/index.html