It is a 2g mobile telecommunications standard that uses cdma, a multiple access scheme for digital radio, to send voice, data and signaling data such as a dialed telephone number between mobile telephones and cell sites. Technical introduction to cdma global technologies. Cdma cellular telephony is 95 is a cellular phone system based on direct sequence cdma multiple access. Cdma cellular systems are deemed superior to fdma and tdma, which is why cdma plays a critical role in building efficient, robust, and secure radio communication systems. The architecture of cdma2000 data system is based on the following components as shown in figure 4. These components can be used for measuring is95 cdma system performance or for speech processing applications. Other countries, including brazil, china, korea, india, japan, new zealand, hong kong, and others, also use cdma. The technicality of cdma technology has given significant advantages over other parallel technologies in terms of spectrum efficiency and overall performance. Is95 cellular system the is95 standard describes a code division multiple access cdma system in which the audio band data signal is multiplied by a high rate spreading signal. Lets take a simple analogy to understand the concept of cdma.
To much noise will cause interference leading to degraded service or dropped calls. Is95 was the first cdma mobile phone system to gain widespread use and it is. Code division multiple access or cdma has its roots in wwii era spread spectrum technology. Cdma architecture based on orthogonal complementary codes, chara cterized by its unique spreading modulation scheme, uplink and downlink signatur e design, and. Is95 system features code division multiple accessfdmafdd traffic channel pair of 1. To permit this without undue interference between the users, cdma. Prasad, an overvies of cdma evolution toward wideband cdma, ieee, 1998. This spreading signal is formed from a pseudonoise code sequence, which is then multiplied by a walsh code for maximum orthogonality to. Pdf comparative analysis of gsm network and is95 cdma.
Doherty, performance characteristics of the is95 standard for cdma spread spectrum mobile communication systems, ieee, 1997. Achieving higher bandwidth efficiency interference limited and simplifying the system planning. Special features of is95 cdma system bandwidth recycling enhancing the system capacity due to the increase of reuse efficiency. It was developed by qualcomm and later adopted as a standard by the telecommunications industry association in tiaeiais95 release published in 1995. Dab, dvb, dmb the missing bit a single architecture to integrate all these and future systems, enabling users to have global reliable connectivity. In april, 2001, china unicom began to construct cdma networksthe largest in the world about 70million line now.
A calling process example is shown for practical system. Cdma is a newer standard, with a higher capacity, and widely used in north. The base station architecture is based on a universal platform that can support cdma and other cellular standards such as amps and tdma in the same base. Screen shot of study area during playback of log file. Cdma network architecture consists of following elements mobile station ms.
This spreading signal is formed from a pseudonoise code sequence, which is then multiplied by a walsh code for maximum orthogonality to ie. Wcdma including the ran radio access network and the cn core network. The ms is the mobile subscriber equipment, which can originate and receive calls and communicate with the bts. Cdma architecture cell breathing cdma is a noisegenerated technology. A design of the codedivision multiple access cdma cellular system architecture is presented. Gsm global system for mobile communications and tdma time division multiple access. This allows several users to share a band of frequencies see bandwidth. This type of sim card mobility is analogous to terminal mobility, but provides a personalmobilitylike service within the gsm mobile network refer to chapter 11 for more details.
This standard will continue using abbreviation and definition in cdmabased digital. Is95 cdma code division multiple access cdma is a wireless spreadspectrum communication technology used in north america by sprint and verizon. The 3g wcdma air interface standard had been designed for alwayson packet based wireless service, so that computers, entertainment devices, and communication device all share the same wireless network and be connected to the internet, anytime, anywhere. In is95 and cdma 2000 we do this three times, once with a code called walsh, then with a code called short code and then with one called long code. An ms has a number of identities including the international mobile. The mobile broadband standard the role of 3gpp maintenance and evolution of radio technologies. Cdmabased networks, there is a clear need for a solid analysis including extensive simulations and radio interface measurements of different. The cdma system uses the same frequency in all cells and all sectors. Gsm, gprs, wcdma, umts, edge, hspa and lte maintenance and evolution of the related core network and systems architecture. It has an open, distributed architecture the separation of switching and service control functions full use of ss7 as the signaling infrastructure its clearly defined and specified interfaces the nature of its in structure general packet radio service gprs and enhanced data rates for global evolution edge cdma, are 3g gsm. Is95 operates in the 800 mhz and 1900 mhz frequency bands. Cdma systems are equipment with a protocol that allows the system to adjust in these situations. Thus, multiple users simultaneously share the same wideband channel.
Cdma code division multiple access is a secondgeneration digital mobile telephone standard which takes a different approach to the other, competing standards. Umts allows many more applications to be introduced to a worldwide base of users and provides a. Code division multiple access cdma linkedin slideshare. Cdma network architecture cdma messaging cdma handset architecture cdma handoff principles cdma system acquisition and call flow examples introduction to optimization and optimization tools whats new in cdma2000. In 1995, cdma technology was put into commercialization in hong kong and america on large scale. Interim standard 95 is95 was the first ever cdmabased digital cellular technology. The is95 cdma system operates in the same frequency band as the amps using frequency division duplex fdd with 25 mhz in each direction. Receiver performs a time correlation operation to detect only desired codeword.
Commercial broadband modem 400 multimission satellite modem the viasat commercial broadband modem 400 cbm400 is the most adaptable satcom modem platform, delivering more bandwidth efficiency, interoperability, and security to mobile, onthepause, and fixed communications. The proprietary name for is95 is cdmaone it is a 2g mobile telecommunications standard that uses cdma, a multiple access scheme for digital radio, to send. Properties of spreading codes multiplication with the code sequence which is of a higher bit rate, results in a much wider spectrum. Mobile communications networks mobile communications. Example of a reverse cdma channel received by a base station. Cdma established the foundation for 3g technologies is95 cdmaone initial cdma standard from qualcomm may 1995 mobile 3g evolved into two competing standards both based on cdma cdma2000 uses 1. With the success of the initial is95 format, improvements were made and the. The ran is used to process all the radiorelated functions, while the cn is used to process all voice calls and data connections within the umts system, and implements the function of external network switching and routing.
The paths loss propagation model is an important tool in wireless network planning, allowing network planner to optimize the cell towers distribution and meet expected service level requirements. Cdma is the base on which access methods such as cdmaone, cdma2000, and wcdma are built. The bts transmits and receives radio signals, realizing communication between the radio system and the mobile station. Chapter 7 multiple division techniques outline frequency division multiple access fdma time division multiple access tdma code division multiple access cdma comparison of fdma, tdma, and cdma walsh codes nearfar problem types of interferences analog and digital signals basic modulation techniques amplitude modulation am frequency modulation fm. An example of soc system design with a heterogeneous multiprocessor target architecture. Codedivision multiple access cdma is a channel access method used by various radio communication technologies. Then we focus on the description of system architecture, which serves as an reference of thorough details. The is95 standard describes a code division multiple access cdma system in which the. Is95 cdma channels types of channels forward channels pilot synchronization paging traffic reverse channels access traffic channels system mon. The system design has been standardized by the tia as is95 and many equipment vendors sell cdma equipment that meet the standard.
Cdma is an example of multiple access, where several transmitters can send information simultaneously over a single communication channel. In is95, all base stations use the same channel c 1. Comparative analysis of gsm network and is95 cdma network using signal strength. 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. Tdma religious tones to debate 1992 tia started study of spread spectrum cellular several. Logically, the cn is divided into the cs circuit switched domain and the ps packet switched. Incremental progress 1g amps data capabilities 30 khz.
The viasat cbm400 is a softwaredefined modem platform. Signaling voicedata signaling voicedata application na 1200 9600 960014,400 4800 960014,400 bitss walsh code 0 walsh code 32 walsh codes 17 walsh 831,3363. Interim standard 95 is 95 is a second generation 2g mobile telecommunications standard based on code division multiple access cdma technology, which guarantees multiple access when sending voice and data between mobile phones and cell sites. Is95 cdma receiver, international symposium on low power electro nics and design, 1999. A set of basic celp codec components are supplied based on tiaeiais96. Ad9235 12bit, 204065 msps 3 v ad converter data sheet. Jeanpaul linnartz, 2007 cdma power control in is95 cdma performance is optimized if all signals are received with the same power update needed every 1 msec. A mobile station in a form of a handset, pda, or pcmcia card in handheldportable computer supporting simple ip or mobile ip client or both. Umts, also referred to as wideband code division multiple access wcdma, is one of the most significant advances in the evolution of telecommunications into 3g networks. Is95 cdma code division multiple access cdma is a wireless spread spectrum communication technology used in north america by sprint and verizon. Gsm and cdma spectrum frequencies the cdma network operates in the frequency spectrum of cdma 850 mhz and 1900 mhz while the gsm network operates in the frequency spectrum of gsm 850 mhz and 1900 mhz. Scalable and flexible cosimulation of soc designs with.
Performance characteristics of the is95 standard for cdma spread. A comparison between is95 and other 2nd generation cellular phone systems is546 gsm is95 tdma fdma cdma hard handoff soft handoff openloop and slow power control closeloop and faster power control fixed rate vocoder variable rate vocoder. As such the system must monitor its noise floor or ambient noise. Other countries including brazil, china, korea, india, japan, new zealand, hong kong and others also use cdma. Cdma20001x radio access network ran packet control function pcf. Suboptimal multipath diversity receiver architecture.
Cdma digital cellular system claimed to increase capacity by factor 20 or more. The proposed multicarrier code division multiple access mc cdma has a great. Designers from qualcomm claim a 20 fold increase in capacity over analog cellular telephony. Kassas department of electrical and computer engineering university of california, riverside joe. At present, cdma commercial networks are established in about 40 countries or area, almost 20% of all users in the world.