Short for Code-Division
Multiple Access, a digital
cellular technology that uses spread-spectrum techniques. Unlike competing
systems, such as GSM, that
use TDMA, CDMA
does not assign a specific frequency to each user. Instead, every
channel uses the full
available spectrum. Individual conversations are encoded with a pseudo-random
digital sequence. CDMA consistently provides better capacity for voice
and data communications than other commercial mobile technologies, allowing more
subscribers to connect at any given time, and it is the common platform on which
3G technologies are built.
CDMA is a military technology first used during World
War II by 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. Because Qualcomm
created communications chips for CDMA technology, it was privy to the classified
information. Once the information became public, Qualcomm claimed patents on the
technology and became the first to commercialize it.
The CDMA Development Group Home page of the CDG (CDMA Development Group), an industry consortium of companies developing CDMA products and services. Here you'll find background information about CDMA as well as updated news stories.
Qualcomm home page Qualcomm, Inc. developed the CDMA technology and is one of the leading providers of CDMA products. Its web site provides corporate information as well as data about CDMA and CDMA products.
Wireless Design Online Excellent resource for those involved in the design and development of wireless communications systems and equipment. Includes news items, a Web resource center, discussion forums, and buyer's guides.
The CDMA Revolution Technical overview of CDMA and how it differs from TDMA-based systems.
