Operates at both and MHz frequency bands 13 Spread Spectrum Multiple Access Technologies 14 Many users of CDMA use the same frequency, TDD or FDD may be used Multipath fading may be substantially reduced because of large signal bandwidth No absolute limit on the number of users Easy addition of more users Impossible for hackers to decipher the code sent Better signal quality No sense of handoff when changing cells 15 As the number of users increases, the overall quality of service decreases Near- Far- problem arises About PowerShow. Whether your application is business, how-to, education, medicine, school, church, sales, marketing, online training or just for fun, PowerShow. And, best of all, most of its cool features are free and easy to use. You can use PowerShow. Or use it to find and download high-quality how-to PowerPoint ppt presentations with illustrated or animated slides that will teach you how to do something new, also for free. Or use it to upload your own PowerPoint slides so you can share them with your teachers, class, students, bosses, employees, customers, potential investors or the world.
|Published (Last):||10 March 2015|
|PDF File Size:||6.95 Mb|
|ePub File Size:||18.78 Mb|
|Price:||Free* [*Free Regsitration Required]|
Assume we have a few students gathered in a classroom who would like to talk to each other simultaneously. Nothing would be audible if everyone starts speaking at the same time. Either they must take turns to speak or use different languages to communicate. The second option is quite similar to CDMA — students speaking the same language can understand each other, while other languages are perceived as noise and rejected. Similarly, in radio CDMA, each group of users is given a shared code.
Many codes occupy the same channel, but only those users associated with a particular code can communicate. Individual conversations are encoded with a pseudo-random digital sequence and then transmitted using a wide frequency range.
CDMA consistently provides better capacity for voice and data communications, allowing more subscribers to connect at any given time. CDMA is the common platform on which 3G technologies are built. This has a single 5 MHz channel. WCDMA uses a single carrier per channel and employs a spreading rate of 3.
It works together to lead the growth and evolution of advanced wireless telecommunication systems. CDG is comprised of service providers, infrastructure manufacturers, device vendors, test equipment vendors, application developers, and content providers.
Its members jointly define the technical requirements for the development of complementary systems CDMA and 4G. Further, the interoperability with other emerging wireless technologies are meant to increase the availability of wireless products and services to consumers and businesses worldwide.
Différence entre FDMA, TDMA et CDMA
cdma tdma fdma
Comparison – FDMA, TDMA and CDMA
CDMA - Introduction