Method and system for facilitating timing of base stations in an asynchronous CDMA mobile communications system

A METHOD AND SYSTEM ARE DISCLOSED FOR FACILITATING THE TIMING (E.G., THE KNOWN RELATIVE TIMING DIFFERENCES) OF BASE STATIONS (BSs) IN ASYNCHRONOUS CDMA MOBILE COMMUNICATIONS SYSTEMS. A PLURALITY OF MOBILE STATIONS (MSs) MEASURE THE RELATIVE TIME DIFFERENCE BETWEEN VARIOUS PAIRS OF BSS, AND THESE MEASUREMENT ARE STORED BY THE BSS. A SOURCE BS SENDS TO AN MS, IN A NEIGHBOR LIST MESSAGE, ESTIMATES OF THE RELATIVE TIME DIFFERENCES BETWEEN THE SOURCE BS AND EACH OF THE BSs ON NEIGHBORING CELL LIST. EACH BS ON THE LIST CAN MAINTAIN A RELATIVE TIME CONTINUOUSLY FROM THE REPORTS RECEIVED FROM MSS. SUBSEQUENTLY, THE BSSS CAN SEND ENTRIES FROM THIS TABLE TO THE MS IN THE NEIGHBOR LIST MESSAGE. USING THIS NOVEL TECHNIQUE, THE BSs HAVE KNOWN RELATIVE TIMING DIFFERENCES. CONSEQUENTLY, WHEN MS INITIATES A CE HAS AN ESTIMATE OF THE TIMING OF THAT BS AS COMPARED TO ITS SOURCE BS. AS SUCH THE RESULTING CELL-SEARCH PROCEDURE HAS A LOWER LEVEL OF COMPLEXITY AND THUS CAN BE ACCOMPLISHED NUCH QUICKER THAN WITH PRIOR PROCEDURES. IN ADDITION, THE RELATIVE TIME DIFFERENCE ESTIMATES CAN BE COMPARED WITH CORRESPONDING TIME DIFFERENCES THAT ARE MEASURED BY A SECOND MS AND VARIOUS BSs CAN BE CALCULATED TO DETERMINE THE POSITION OF THE SECOND MS.[FIGURE 1]