MOBILE COMMUNICATION 3G CDMA


ABSTRACT

Cellular technology
Developed by Quamcomm
Originally known as IS-95
Competes with GSM
CDMAONE,CDMA2000
Variants 1XEV,1XEV-DO,MC3X

INTRODUCTION

What is CDMA
Multiple Access Comparison
FDMA - Frequency Division Multiple Access
TDMA - Time Division Multiple Access
CDMA - Code Division Multiple Access

BENEFITS Of CDMA
Cdma capacity increases
Improved call quality
Simplified system planning
Enhanced priva ....etc

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DS-CDMA in Wireless Handset Communication Using MATLAB.
code
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BackGround
A CDMA (Code Division Multiple Access) based communication system allows the users to share an available frequency spectrum. The users are allocated different codes that are recognizable for the preferred receivers. This solution has several advantages, among other it gives increased robustness to interference. The CDMA project will investigate the benefits and losses of using CDMA communication system on an acoustic channel between two computers. The focus of the project will be to study how a higher data rate will affect ....etc

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(Code Division Multiple Access) A method for transmitting real-time signals over a shared portion of the spectrum. The foremost application of CDMA is the digital cellular phone technology that operates in the 800MHz band and 1.9GHz . Unlike GSM and TDMA, which divides the spectrum into different time slots CDMA uses a spread spectrum technique to assign a code to each conversation. After the speech codec converts voice to digital, CDMA spreads the voice stream over the full 1.25MHz bandwidth of the CDMA channel coding each stream separately s ....etc

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1. INTRODUCTION
As more and more attention is paid to the ocean, the requirement of exploration and exploitation to it grows increasingly. In order to realize some tasks in the ocean such as collection of the information, monitoring of the environment, exploration of energy sources, forecast of natural disaster, assistant navigation, underwater communication technique has become a very important scientific research field. Because acoustic wave is adopted to actualize communication in the water instead of electromagne ....etc

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Distributed Medium Access Control for Next Generation CDMA Wireless Networks

Generic Distributed Network Model
we focus on a generic network model where a number of wireless mobile nodes are organized in a flat fashion, communicating with each other via one-hop or multiple-hop connections without any central control. Connections to outside correspondence nodes are supported through a gateway (e.g., in the wireless backbone) or an access point (e.g.,in ad hoc networks or WPAN).
In ....etc

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CDMA Communication System ....etc

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CDMA Technology

Abstract :

CDMA was developed by QUALCOMM Incorporated, a company in San Diego, California. QUALCOMM engineers decided to do something different and applied spread spectrum techniques to a multiple access system, which ultimately became CDMA.
In spread spectrum, instead of giving each person a channel, or each group of 3 or 8 people a time slot, CDMA puts everyone in the same channel at the same time.
At first thought, it would seem to be an impossible task to make work, but it does work. The reason it works is expla ....etc

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CDMA Mobile Communication & IS-95
 Most of the slides are stolen from Prof. Abhay Karandikar’s lecture
 Spread Spectrum Priniciples
 Does not attempt to allocate disjoint frequency or time slot resources
– Instead, this approach allocates all resources to simultaneous users, controlling the power transmitted by each user to the minimum required to maintain a given SNR
 Each user employs a noise-like wideband signal occupying the entire frequency allocation
 Each user contributes to the back ....etc

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ABSTRACT
Machine health monitoring is of critical importance to its safe and reliable operation. The emergence of wireless data transmission techniques has extended the Scope of health monitoring to machine components and systems that are difficult to accessor not suited for wired sensor data acquisition .this paper presents the design and prototype realization of a digital wireless data transmitter based on the CDMA technique.
The design provides a generic solution for various applications ....etc

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