It works by adding a scrambling code to a signal so that multiple signals can be transmitted to the same channel and the user can select the desired signal by applying his scrambling code as part of a signal removal process. CDMA technology is used in a number of mobile phone systems such as Qualcomm CDMOIN (IS-95) and its extensions, CDMA 2000, as well as UMTS 3G systems in the GSM family.
