CDMA code division multiple access CDMA is a digital spread-spectrum modulation technique used mainly with personal communications devices such as mobile phones. CDMA digitizes the conversation and tags it with a special frequency code. The data is then scattered across the frequency band in a pseudorandom pattern. The receiving device is instructed to decipher only the data corresponding to a particular code to reconstruct the signal. See also: spread spectrum, frequency spectrum, S-CDMA