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wideband cdma


WCDMA is a wideband spread-spectrum 3G mobile telecommunication air interface that utilizes code division multiple access (or CDMA the general multiplexing scheme, not to be confused with CDMA the standard). It provides simultaneous support for a wide range of services with different characteristics on a common 5MHz carrier.

The term WCDMA also refers to one of the International Telecommunications Union’s IMT-2000 standards, a type of 3G cellular network. WCDMA is the technology behind the 3G UMTS standard and is closely allied with the 2G GSM standard. It provides new service capabilities, increased network capacity and reduced cost for voice and data services.

The term ‘WCDMA Evolved’ describes the evolution of WCDMA, addressing both operators’ needs for efficiency and users’ demands for enhanced experience and convenience. The first steps of this evolution are HSDPA and Enhanced Uplink.

Technical features
Only key features are cited below.
Radio channels are 5MHz wide.
Chip rate of 3.84 Mcps
Supports two basic modes of duplex: frequency division and time division. Current systems use frequency division, one frequency for uplink and one for downlink. For time division, FOMA uses sixteen slots per radio frame, whereas UMTS uses fifteen slots per radio frame.

Employs coherent detection on both the uplink and downlink based on the use of pilot symbols and channels[1].

Supports inter-cell asynchronous operation.

Variable mission on a 10 ms frame basis.

Multicode transmission.

Adaptive power control based on SIR (Signal-to-Interference Ratio).

Multiuser detection and smart antennas can be used to increase capacity and coverage.

Multiple types of handoff (or handover) between different cells including soft handoff, softer handoff and hard handoff.

Introduction to CDMA

CDMA Basics Tutorial

CMOS Dual-Mode RF Front-End Receiver for GSM and WCDMA articles

A Velocity Estimation-Based Channel Estimator for WCDMA Forward Link Receiver aricle

Online articles, references, and resources on CDMA

CDMA vs TDMA Discussion on CDMA and TDMA

Code Division Multiple Access Concept of signal spreading

Optimization of Idle-Mode Receiver Measurements in WCDMA

Optimum Antenna Downtilt Angles for WCDMA Network

The Maximum Available Radio Resource of a WCDMA Downlink

WCDMA Direct-Conversion Receiver Front-End Comparison in RF-CMOS and SiGe BiCMOS

WCDMA Radio Network Planning lecture notes< Wideband CDMA System lecture notes

Wideband Code Division Multiple Access tutorial

CDMA basics including access schemes, coding, codes, the spreading process, power control, handover, multipath and rake receivers

CDMA Basics Tutorial
Tutorial and information of the basics about the way direct sequence spread spectrum (DSSS) can be used to provide the CDMA (code division multiple access) technology for mobile, cell or cellular phone systems, or any other system

CDMA Technology
Information on CDMA technology including comparisons to the two traditional ways of multiple access, Frequency Division Multiple Access (FDMA) and Time Division Multiple Access (TDMA).

Introduction to CDMA
introduction to Code Division Multiple Access (CDMA) communications, covering a Radio Carrier Station (RCS) and a Fixed Subscriber Unit (FSU)

Cooperative Control of WCDMA System

CDMA to GSM WCDMA Migration white paper

WCDMA Outphasing Power Amplifier With a Software Defined Transmitter/Receiver Architecture for Determination of the Predistortion Function

Definition of W-CDMA
W-CDMA (Wideband Code Division Multiple Access), a type of 3G cellular network, is the higher speed transmission protocol used in the Japanese FOMA system and in the UMTS system, an advanced 3G system, designed as a replacement for the ageing 2G GSM networks deployed worldwide
Innovations in WCDMA
Basic concepts of HSPA
HSPA, the undisputed choice for mobile broadband
Services in the Basic concepts of HSPA
Wireless networks for in-building environments
Full service broadband architecture

WCDMA (or W-CDMA) stands for Wideband Code Division Multiple Access. WCDMA is direct spread technology, which means that it will spread its transmissions over a wide, 5MHz carrier. Hence the name W (wideband) CDMA. WCDMA is the leading 3G wireless standard in the world today. It was adopted as a standard by the ITU under the name “IMT-2000 direct spread.” WCDMA is the technology used in the Universal Mobile Telecommunications System (UMTS), and with data rates up to 2Mbits it has the capacity to easily handle bandwidth-intensive applications such as video, data, and image transmission necessary for mobile internet services. Operators such as Vodafone, Singtel, AT&T and TIM have chosen WCDMA/UMTS as their 3G solution.

After slow growth for many years, it appears that 3G/WCDMA/UMTS is finally taking hold — preliminary figures indicate that as 2005 closed, there were 44 million W-CDMA subscribers worldwide, an increase of 164% over the number registered at the end of 2004.

The articles, resources and links

Reference books

Introduction to Wideband Code Division Multiple Access (WCDMA) (Paperback) , by Lawrence Harte . Paperback- 108 pages (August 2004).

WCDMA (UMTS) Deployment Handbook: Planning and Optimization Aspects , by Christophe Chevalier et al (Editors). Hardcover – 412 pages (September 29, 2006).

WCDMA: GPRS and 3G Wireless Applications: Professional Developer’s Guide, by Christoffer Andersson. Paperback – 352 pages Bk&Cd-Rom edition (April 11, 2001).

UMTS Mobile Communications for the Future, by Flavio Muratore (Editor). Hardcover – 264 pages (January 16, 2001).

UMTS Networks: Architecture, Mobility and Services, by Heikki Kaaranen (Editor), Siamäk Naghian, Lauri Laitinen, Ari Ahtiainen, & Valtteri Niemi. Hardcover – 384 pages 1st edition (August 14, 2001).

The UMTS Network and Radio Access Technology: Air Interface Techniques for Future Mobile Systems, by Jonathan P. Castro. Hardcover – 384 pages 1 edition (April 4, 2001).

Good lecture notes

“WCDMA for UMTS. 

Radio Access For Third Generation Mobile Communications.” 

Introduction to 3G systems. Radio channel models.

slides

Evolution from GSM to UMTS.

slides

User traffic modeling for future mobile systems.

Tapani Nieminen

slides

Introduction to WCDMA.

slides

User traffic modeling for future mobile systems.

slides

You might be interested also on a version of this lecture from the last year course givben by mr. Atte
Länsisalmi from Nokia Reserach Center 

slides 2001

WCDMA Physical Layer
slides

WCDMA Radio Interface Protocols
slides

WCDMA Radio Network Planning
slides

WCDMA Packet Access
slides


WCDMA Radio Resource Management

slides

WCDMA Physical Layer Performance
slides





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  1. Guru

    Code Division Multiple Access (CDMA)
    An air interface technology that was developed by the U.S. military and commercialized by the U.S. company Qualcomm. CDMA assigns a code to all speech bits, sends a scrambled transmission of the encoded speech over the air and reassembles the speech to its original form at the other end. CDMA supports SMS with a message length of 120 characters. With CDMA, each conversation is digitized and then tagged with a code. The mobile phone receives a signal to locate that particular code and it then deciphers the conversation off the airwaves. It codes each conversation expanding it 128 times, making it easy to decipher at the receiving end.

  2. TDMA

    Time Division Multiple Access: A method of digital wireless-communications transmission. TDMA allows many users to access (in sequence) a single radio-frequency channel without interference, because it allocates unique time slots to each user within each channel.

  3. amisha

    it is very very useful materials.thank u very very much



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