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Code division multiple access (CDMA) is a channel access method used by various radio communication technologies. It should not be confused with the mobile phone standards called cdmaOne and CDMA2000 (which are often referred to as simply CDMA), which use CDMA as an underlying channel access method. One of the basic concepts in data communication is the idea of allowing several transmitters to send information simultaneously over a single communication channel. This allows several users to share a bandwidth of different frequencies. This concept is called multiplexing. CDMA employs spread-spectrum technology and a special coding scheme (where each transmitter is assigned a code) to allow multiple users to be multiplexed over the same physical channel. By contrast, time division multiple access (TDMA) divides access by time, while frequency-division multiple access (FDMA) divides it by frequency. CDMA is a form of spread-spectrum signaling, since the modulated coded signal has a much higher data bandwidth than the data being communicated. An analogy to the problem of multiple access is a room (channel) in which people wish to communicate with each other. To avoid confusion, people could take turns speaking (time division), speak at different pitches (frequency division), or speak in different languages (code division). CDMA is analogous to the last example where people speaking the same language can understand each other, but not other people. Similarly, in radio CDMA, each group of users is given a shared code. Many codes occupy the same channel, but only users associated with a particular code can communicate. From Wikipedia under the
GNU Free Documentation License Can an iPhone be converted to CDMA from GSM for use on Verizon or Sprint? Q. I understand that GSM and CDMA are two different communication languages. Can the software in the iphone be altered so that it can speak CDMA language? Does it require a hardware change? Has anyone accomplished the conversion? Asked by sanjoseskater - Tue Apr 1 17:19:42 2008 - - 1 Answers - 0 Comments A. Your first question: can't be done. Such a conversion would require software and hardware changes, something the normal person wouldn't be able to afford, much less execute. You're better off purchasing the iPhone-like CDMA phones offered by Verizon Wireless, et al. Answered by CMass Stan - Tue Apr 1 17:25:01 2008 Is there any device or method to locate a CDMA cellular phone that is likely being carried by a missing person? Q. We are trying to help locate a missing relative in India. The missing person has a CDMA cell phone, but efforts to locate the last cell tower that the phone communicated with so far are unsuccessful. If the general vicinity of the area (a trekking area) is know, is there any way to further pinpoint their location? Asked by tahoe-pinetop - Thu Feb 5 03:29:53 2009 - - 1 Answers - 0 Comments A. might be too much tv talking but can't they triangulate a signal using the towers around the area? Answered by Adrian777 - Thu Feb 5 03:33:25 2009 How can you create a wireless Internet acess at home using an Internet-enabled wireless CDMA phone?
Q. The CDMA phone provides Internet access when plugged into the computer without having to dial the phone, that is, it instantly gives you access to the Internet once plugged into the computer. Asked by paulidee - Mon Jan 22 01:02:39 2007 - - 1 Answers - 0 Comments A. you need a data cable or you can connect ur phone to ur pc via bluetooth then u need proper driver for that which u get with the cable install it and u r ready to go. Answered by divas - Mon Jan 22 01:10:28 2007 From Yahoo Answer Search: "CDMA"
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CDMA Mobile Communication Networks Research
Adaptive Interference Rejection for CDMA.
