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Post by tapesh on Mar 29, 2010 23:56:52 GMT -5
i want to know about modulation techniques used in mobile communication.  as the mobile technology has grown to 3-G, since 1-G, what has been the changes and add ups and updates in the modulation techniques.  i feel modulation techniques must have been playing a pivotal role in bring 3-G technology. help me out, with links, pdfs and threads  sincerely |
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Post by jsolar on Mar 30, 2010 12:44:20 GMT -5
Good question. I can;t help you out with links and threads, but I can give you buzz words to google.
To squeeze more Ehrlang's out of a path modulation has been moved from constant amplitude to at least a controlled crest factor. CDMA has always required AM and thus was not as power efficient in the amplifier of the mobile unit. But now with more signal processing horsepower the move is to wider BW and to a more complex OFDM. Also, the virtually free lunch promised by MIMO is paying out in 3G and more so in 4G. Linking the coding with the modulation has brought some advantages. Security is enhanced by putting the security coding on the modulation pattern. These are some general coments that contain the gist, you can get the technical details on the web somewhere I assume. You can also go to the 3GPP standards and read the modulation section. It is very boring and does not tell you why or what the advantages are, but you will get the gory detail.
Good Luck!
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as the mobile technology has grown to 3-G, since 1-G, what has been the changes and add ups and updates in the modulation techniques. 
