CDMA
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Motohiro Ichinose
CDMA
Code Division Multiple Access (CDMA)
A digital wireless technology that uses a "spread
spectrum" technique to scatter a radio signal across
a wide range of frequencies. CDMA provides
greater total capacity than other technologies, along
with outstanding voice quality and fewer dropped
calls. CDMA is the technology of choice for new
third-generation systems
CDAM (history)
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CDMA is a military technology first used during
World War II by the English allies to foil German
attempts at jamming transmissions. The allies
decided to transmit over several frequencies,
instead of one, making it difficult for the
Germans to pick up the complete signal.
CDMA(code division multiple access)
Advantage of using CDMA
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Noise reduction
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Secrecy
Spread singnal
How to spread
Transmit, receive and noise reduction
IMT-2000 begins last year
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Celluer phone
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Foma (w-cdma) 384kbps
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9.6kbps
2Mbps