It is the technique by which same frequency and time interval is used by mobile subscribers base stations by way of unique digital codes. Rc radio configuration defines the physical channel configuration based upon a base channel data rate. These concepts are cdma specific, and often not used in other technologies, so some explanation may be necessary. Code division multiple access cdma is technology for digital transmission of radio signal in telecommunication systems.
This is achieved by a specific but complex mathematical function. Principles of code division multiple access cdma professor a. In this technology, multiple users can transmit the data simultaneously in a channel using same frequency. Wcdma for umts principles introduction cdma background history key parameters code division multiple access cdma why cdma. Telecommunications network and service architectures. Designing and testing 3gpp wcdma base transceiver stations. Hybrid multiple access schemes like multicarrier fdma, multicarrier. The network used to connect the telephonetotelephone exchange. Comprehensive and up to date information about the is2000 1x releases a through d, including 1xevdv, as well as 1xevdo or is856 revisions 0 and a standards.
Cellularpcs systems implementation offers both practical applications information and conveniently organized reference materials for anyone interested in the next generation of wireless telecommunications. This cdma tutorial describes cdma basics by explaining pn sequence codes, walsh codes,cdma physical layer for base station and mobile subscriber. Cdma code division multiple access or cdma has its roots in wwii era spread spectrum technology. Introduction to cellular mobile radio communication the subject of this book is code division multiple access cdma communications. Nonlte basic concepts lte vs nlte occupation numbers rate equation transition probabilities. A general awareness of some basics of telecommunications is sufficient to understand the concepts explained in this tutorial. Adopted in 1993 by the telecommunication industry association, the cdma standard is95 is the embodiment of many of the principles presented in this text. This book uniquely ties together all the different concepts that form the mobile radio. The technicality of cdma technology has given significant advantages over other parallel technologies in terms of spectrum efficiency and overall performance. Thus, for this asymmetric structure it is very important to understand the multicarrier spread spectrum methods. The cdma development group states that, as of april 2014, there are 314 operators. Dscdma directsequence code division multiple access is a multiple access scheme based on dsss, by spreading the signals fromto different users with different codes. The connection between telephone and exchange can be two copper wires or radio wave. The course will progress and provide some basic radio communication terms and concepts before.
Intuitive guide to principles of communications orthogonal frequency division multiplexing ofdm modulation a mapping of the information on changes in the carrier phase, frequency or amplitude or combination. Boost your skills with onsite courses tailored to your needs. This textbook takes a unified view of the fundamentals of wireless communication and explains the web of concepts underpinning these advances at a level accessible to an audience with a basic background in probability and digital communication. The basic principle of cdma is that different codes are. Principles, protocols and practice, release techniques allow to create pointtopoint links while radiobased techniques, depending on the directionality of the antennas, can be used to build networks containing devices spread over a small geographical area. The book emphasizes cdma because nextgeneration standards are based on that multipleaccess technology. The bandwidth of the coded data signal is chosen to be much larger. In cdma each user is assigned a unique code sequence it uses to encode its informationbearing signal. Wideband cdma radio transmission technology the university. The various concepts covered are brought together in a description of wireless communication, using cdma as a case study. In ofdma, both time and frequency are distributed among users. Cdma is a method in which users occupy the same time and frequency allocations, and are channelized by unique assigned codes. In developing the harmonized global cdma 3g standard, the following principles and.
Code division multiple access cdma is a channel access method used by various radio communication technologies. It is required two wires to connect the telephone and. Cdma principles spreading codes multipath radio channel and rake receiver problems to solve macro diversity and soft handover nearfar problem and power control umts general requirements fdd vs. The goal of cdma is to break up a finite radio frequency so that multiple users can access it at the same time. What really is a third generation 3g mobile technology pdf. The receiver, knowing the code sequence of the user, decodes the received signal and recovers the original data. The knowledge you gain taking teracoms online courses, confirmed with tco certification, is foundational knowledge in telecommunications, ip, networking and wireless. Cdma scheme has two concepts, spread spectrum techniques with single user detection and multi user concepts with joint detection of user signals. Andrew j viterbi spread spectrum multiple access communication, known commercially as cdma code division multiple access, is a driving technology behind the rapidly advancing personal communications industry. In ofdmtdma, timeslots are attributed to each users and the whole ofdm symbol is dedicated to one user. Pdf code division multiple access cdma implementation. Code division multiple access cdma communication is rapidly replacing time and frequencydivision methods as the cornerstone of wireless communication and mobile radio. Difference between 3g and cdma tweet key difference.
This tutorial provides an introduction to basic gsm concepts, specifications, networks, and services. Provides a brief overview of wcdma technology and femtocells. Cdma can be implemented in several ways, two of which are frequency hopping and direct sequencing. To implement this concept of providing cdma services on an existing gsm network, it. The applied technology institute specializes in training programs for technical. Fdma, tdma, cdma, ofdma, and sdma here are the pdf versions of these articles. Cellular network organization use multiple lowpower transmitters 100 w or less areas divided into cells oeach served by its own antenna oserved by base station consisting of transmitter, receiver, and control unit oband of frequencies allocated ocells set up such that antennas of all neighbors are equidistant hexagonal pattern. Cdma is also full duplexcdma is also full duplex us cellular channel 384 frequency amplitude frequency amplitude amps 45 mhz 80 mhz pcs forward link 836. Pdf principles of communication download read online. Cdma i about the tutorial code division multiple access cdma is a channel access method normally used by 3g radio communication technology as well as in some other technologies.
Theory of code division multiple access communication provides a lucid introduction and overview of cdma concepts and methods for both the professional and the advanced student. A major application of cdma is wireless communication including mobile radio. A presentation of cdma2000 technology from the fundamental concepts, architectures and protocols to the network engineering and planning principles. Pierre lescuyer and thierry lucidarm, evolved packet system. Pdf wcdma system standardization, interfaces and power. Tarmo anttalainen, introduction to telecommunications, network engineering, 2nd edition, artech house, 2003. Fundamentals of communications access technologies. Cdma is the short form of code division multiple access.
Cdma uses spreadspectrum technology to minimize the problems. If copper wires are used it is called wired connection. Analysis and intuitive interpretations are developed for channel noise models, followed by coverage of the principles of detection, coding, and decoding. Code division multiple access cdma is a multiple access technology where the users are separated by. Communication protocols computer network data transmission. In this chapter we introduce the basic concepts of mobile radio. Cdma is an example of multiple access, where several transmitters can send information simultaneously over a single communication channel. Cdma is one of the applications of spread spectrum communications which is used in civilian, commercial and military communication.
A short history of network evolution is provided in order set the context for understanding gsm. Click to edit master subtitle style page 8 is2000 terms and definitionsis2000 terms and definitions chip is the period of a data bit at the final spreading rate sr spreading rate defines the final spreading rate in terms of 1. Theory of code division multiple access communication. In cdma each user is assigned a unique code sequence spreading code, which it uses to encode its data signal. A conceptual diagram of the harmonization required to achieve these. While the cdma2000 system, which supports cdma over wider bandwidths for capacity improvement and higher data rates, will maintain backward compatibility.
Introduction to radio concepts course description in this course the basic concepts of radio principles are introduced starting with an overview of the electromagnetic spectrum, with a primary focus on the area of radio communications. The information is carried by a signal, which is certain physical quantity that changes with time. Wcdma system standardization, interfaces and power control. The european community has mandated a harmonized standard, gsm, in the 2g bands, and has adopted wideband cdma wcdma in the 3g bands. General packet radio service, mcgrawhill professional, december 2001. Through randomization of frequencies, cdma divides the radio frequency spectrum to share the space for. The signals are separated at the receiver by using a correlator that accepts only signal energy from the desired channel. Principles of code division multiple access in this chapter some basic concepts of cdma are discussed.
Comprehensive and up to date information about the is2000 1x releases a through d, including 1xevdv, as well as 1xevdo or is856 revisions 0. Code division multiple access cdma implementation by matlab. In 1985, the fcc allocated three frequency bands to spread spectrum communications. Cdma2000 is a family of 3g mobile technology standards for sending voice, data, and. Using spreadspectrum technology allows for the signals to be transmitted over a wide spectrum of the electromagnetic spectrum. Basics idea about cdma technology and its applications. Scribd is the worlds largest social reading and publishing site. The basics of code division multiple access jeanpaul m. Cdma tutorial pdf version quick guide resources job search discussion code division multiple access cdma is a channel access method normally used by 3g radio communication technology as well as in some other technologies. Manikas imperial college london ee303 communication systems an overview of fundamentals prof.
Telecommunications basics the purpose of any telecommunications system is to transfer information from the sender to the receiver by a means of a communication channel. Although mccdma performs better than mcdscdma, it needs chip synchronization between users, and is therefore dif. Jeanpaul linnartz, 2007 cdma outline multiple access methods fdma, tdma, cdma spread spectrum methods frequency hopping direct sequence more on code sequences. Multiplexing method of sharing a bandwidth with other independent data channels.
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