TAILIEUCHUNG - Lecture Wireless and mobile computing – Chapter 31: Software defined radio
The following will be discussed in this chapter: Motivations, motivations - efficient and effective frequency allocation, software defined radio, block diagram of a digital radio system, digital radio system | Software Defined Radio Lecture 31 The term "software defined radio" was coined in 1995 by Stephen Blust, who published a request for information from Bell South Wireless at the first meeting of the Modular Multifunction Information Transfer Systems (MMITS) forum in 1996, organized by the USAF and DARPA around the commercialization of their SPEAKeasy II program If the frequency is trapped then they are stuck and can not do anthing SDR is a radio communication system where components that have been typically implemented in hardware (. mixers, filters, amplifiers, modulators/demodulators, detectors, etc.) are instead implemented by means of software on a personal computer or embedded system. Motivations Quad-band GSM GPS Bluetooth . GPRS EDGE WCDMA LTE Large # of Standards and large number of independently developed Radio Boards All Squeezed into the smart device You see one antenna but there are actually a lot 3 or 4 or more Cram Down the funnel of functions New Standards GSM use SIM cards in order to hold all of your data and to be able to connect to the network effectively. GSM is used to talk, text, and use the internet. CDMA: Code Division Multiple Access, not as prominent as it once used to be. These do not use SIM cards, but instead the carrier ties your number and account to the phone itself to connect to the network. CDMA is used to talk, text, and use the internet. LTE: Long Term Evolution, this is the newest form of cellular data. Often referred to as 4G, this is a new, blazing fast mobile data bandwidth. LTE is used for solely internet at the moment, however soon your cell phones may talk over LTE as well. In the US, T-Mobile and AT&T use GSM, while Verizon and Sprint use CDMA. All four networks have LTE in the works, with Verizon having coverage in more than 200 markets already, and AT&T with only around 10 markets. The other carriers are releasing their versions of 4G soon. GSM and CDMA are two of the major networks used in the United .
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