FDMA, TDMA, and CDMA

My first master thesis is about mobile computing at a Computer Science and Engineering department. I remembered learning those knowledge about mobile computing and wireless communication was very interesting and exciting because those technology are so powerful and change the way people communicate totally.

People are talking about FDMA (frequency division multiple access), TDMA(time division multiple access), and CDAM (code division multiple access) when talking about how to utilize wireless signal channel to communicate with each other. There is a very easy example to understand their difference:

There is a room (one wireless signal channel) in which people wish to communicate with each other. To avoid confusion, people could take turns speaking (time division), speak at different pitches (frequency division), or speak in different languages (code division). People speaking the same language can understand each other, but not other people.

Therefore, with using those 3 methods, even sharing the same channel, different pairs of people can talk with each other at the same time without any problem.

So....do you understand it?