CDMA

Code-Division Multiple Access (CDMA) is a digital cellular technology that utilises spread spectrum techniques. Unlike competing systems, such as GSM, that use time-division multiplexing, CDMA does not assign a specific frequency to each user. Instead, every channel utilises the full available spectrum. Individual conversations are encoded with a pseudo-random digital sequence. CDMA enhances the use of available bandwidth. It is a form of multiplexing, which enables numerous signals to occupy a single transmission channel, optimising the use of available frequencies. CDMA employs analogue-to-digital conversion (ADC) in combination with spread spectrum technology. The technology's audio signals are digitised, reducing the signal into binary elements. The frequency of the signals is then spread over a potential area much wider than the minimum bandwidth requirements. This results in a frequency spectrum that appears much like background noise.