CDMA Mobiles
What is CDMA?
You will know CDMA as 'code division multiple access. It is known to fall under the 2G and 3G mobile technology and it uses digital system for transmitting data and voice. The CDMA system is the common base from where 3G technology is developed.
It was the company Qualcomm that first made the CDMA system popular. It was also used by Britain and their allies during the Second World War so that their German enemies will not be able to disturb or tap into the signals being used to relay classified information.
CDMA is different from FDMA and TDMA. FDMA or frequency division multiple access' is a 1G technology that divides channel access by frequency. Subscribers uses two frequencies each for sending and for receiving. TDMA on the other hand is 'time division multiple access' which divides channel access by time.
CDMA mobiles are popular because it allows several benefits to its users. For one, CDMA covers greater areas than other technologies so more users can make their calls. Also, because it makes use of bigger cells that are more sensitive to picking up lower signals, phones that have very low signal reception can still connect. Finally, CDMA mobiles use lesser power than mobiles using other technology so CDMA mobiles may be used longer.
How Does CDMA Work?
CDMA mobiles uses a coding system as suggested by the letters 'CD' meaning 'code division' to enable communication. In this coding system, different transmitters managing groups of phone users are assigned specific codes. These codes are transmitted in a certain range of frequency. After this happens, users who have been assigned similar codes will be able to connect to each other and communicate.
The coding system used by CDMA mobile may also be likened to a method called spread-spectrum. In this method, the energy produced from a specific bandwidth used by a mobile phone is scattered in a frequency domain. This process enables voice transmission security from tapping or detection and from disturbances by natural causes.
