CDMA, or Code Division Multiple Access, is a channel access method that allows multiple users to access the same communication channel simultaneously through the use of unique codes. It works by assigning each connection a unique code, and then allowing users to transmit concurrently over the same frequency. Some key applications of CDMA include use in cell phone networks, GPS systems, and satellite communication systems.

1. CODE DIVISION
MULTIPLE ACCESS

2. WHAT IS THE FULL FORM
OF CDMA?
• The full form of CDMA is Code Division Multiple Access.
• It is a method of channel access and is an example of multiple access as
well.
• Multiple access states that data can be transmitted simultaneously to a
single communication channel through several transmitters.
• Variant CDMA codes are issued or allocated to several users and thus users
can access the entire frequency band or bandwidth as the whole.
• This technique does not restrict the user’s range of frequencies.
• Therefore, without any unnecessary interference among multiple users to
share a frequency band with the aid of CDMA.
• Along with ADC (analogue to digital conversion), CDMA enables the use of
spectrum technology

3. A BRIEF HISTORY
OF CDMA :
• For a long time, CDMA software was in use.
• In 1935, Dmitry Ageev addressed this subject for the very first time.
• During the World War II era, CDMA has also been used to stop the jamming
transmission attempts.
• It was then applied in the military sector which was used in ranging, anti-
jamming and so on.
• It was used by Leonid Kupriyanovich in 1957 when he was creating an
automated wearable mobile phone design.
• Ultimately, in 1993, the specifications for CDMA technology were approved
by the TIA (Telecommunications Industry Association).
• Sixteen million users were registered in September 1998 for the use of
CDMA systems.

4. FEATURES OF CDMA
• At a defined time, it enables more users to communicate and thus offers
enhanced capacity for voice and data communication.
• Many of the channels in CDMA use a complete spectrum.
• To reduce interference & noise and thereby increase the efficiency of the
network, CDMA systems make use of power control.
• To protect its signals, CDMA encodes user transmissions into separate and
special codes.
• The same frequency can also be used by all cells in CDMA systems.
• There is also no fixed limit to the number of participants in a CDMA system,
but performance degrades with an increment in the number of
participants.

5. APPLICATIONS OF
CDMA
• CDMA is used in the GPS (Global Positioning System)Several cell phone firms use
this technology.
• The UTMS 3 G cell phone standard uses W-CDMA.
• CDMA was used in the OmniTRACS transportation satellite system.

6. Thank….
….You
By :-
1] Ashwin Pinto.
2] Shivanand Jana.
3] Shalom Salve.
4] Aditys Walte.