CDMA is a digital wireless technology that uses spread spectrum technique. It was pioneered and commercially developed by QUALCOMM. The first CDMA system was launched in 1995 in Hong Kong and Korea. CDMA uses a PN code generator at the transmitter and receiver to spread the data signal over a wide frequency band. It allows multiple users to be multiplexed over the same physical channel along with supporting soft handoffs between cells. However, its performance decreases as the number of users increases and it has limitations in terms of coverage, roaming, and not supporting SIM cards for mobile commerce applications.

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2. AGENDA
 Introduction.
 What is Spread Spectrum.
 Architecture of CDMA.
 Application of CDMA.
 Limitations of CDMA.
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3. INTRODUCTION
 CDMA is a digital wireless technology.
 It uses Spread Spectrum technique.
 It was pioneered and commercially developed by QUALCOMM .
 Interim Standard-95 , standards for first generation CDMA cellphone
technology.
 The first CDMA system was launched in September 1995 by Hutchison
Telephone Co. Ltd. in Hong Kong and SK Telecom in Korea.
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4. Spread Spectrum Technique
Carrier + Carrier +
Data Data
PN code PN code
Generator Generator
TRANSMITTER RECEIVER
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5. ARCHITECTURE OF CDMA
MS M SC PSTN
Um E Ai
Abis A B
BT S BSC M S C/SSP VLR
BSS
Q C D
M N N
MC MC HLR AUC
MSS
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6. APPLICATION OF CDMA
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7. ARCHITECTURE OF CDMA
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8. LIMITATIONS OF CDMA
 As the number of users increases its performance decreases.
 ‘FAR-NEAR’ problem.
 It is limited in terms of Coverage and Roaming.
 It does not have a SIM card that makes M-Commerce difficult.
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9. THANK YOU
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