Synchronization

To make this transmission method work it is not enough just to have a fancy coding scheme. To keep track of all this information flying back and forth we need to synchronize it with a master clock. As the CDG puts it, "In the final stages of the encoding of the radio link from the base station to the mobile, CDMA adds a special "pseudo-random code" to the signal that repeats itself after a finite amount of time. Base stations in the system distinguish themselves from each other by transmitting different portions of the code at a given time. In other words, the base stations transmit time offset versions of the same pseudo-random code."

Arrgh. Another phrase with the word 'code in it, one more term to keep track of! Don't despair. Even if "pseudo-random code" is fiercesomely titled, it's chore is simple to state: keep base station traffic to its own cell site by issuing a code. Synchronize that code with a master clock to correlate the code. Like putting a time stamp on each piece of information. CDMA uses The Global Positioning System or GPS, a network of navigation satellites that, along with supplying geographical coordinates, continuously transmits an incredibly accurate time signal.