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CDMA vs. TDMA
By qwcdirect | April 7, 2010
CDMA refers to code-division multiple access. TDMA refers to time division multiple access.
Each technology essentially achieves the same goal, but by using different methods. Where the two competing technologies differ is in the manner in which users share the common resource. TDMA does it by chopping up the channel into sequential time slices. Each user of the channel takes turns transmitting and receiving in a round-robin fashion. This is very similar to how a computer with just one processor can seem to run multiple applications simultaneously.
CDMA on the hand really does let everyone transmit at the same time. What makes CDMA work is a special type of digital modulation called “Spread Spectrum”. This form of modulation takes the user’s stream of bits and splatters them across a very wide channel in a pseudo-random fashion. The “pseudo” part is very important here, since the receiver must be able to undo the randomization in order to collect the bits together in a coherent order.
Topics: Mobiles / Cell Phones, Technology | No Comments »