Software Defind Rodios for Third Genration ( SDR for 3G )

Abstract

The worldwide standards bodies have developed multiple standards for high- and low-tier cellular and PCS. While each carrier has plans for offering service based on a specific standard, the multiplicity of standards results in the reduceability for customers to roam into different areas. As new standards for IMT-2000 is developed, still additional radio link interfaces are needed. Clearly, a service provider needs a solution to support multiple standards and the growth to a common worldwide standard. Even when there is one standard, it will not be static but will have revisions. There are two possible approaches for solving the roaming problem. Each customer could have a multimode phone that supports several different air interfaces. The second solution is for each BS to transmit pilot signals that would allow any handset to access the network. While some industry attention has been focused on multimode handset, most of the attention has been on AMPS/one digital technology handsets. While it's possible to make a handset that supports AMPS/CDMA/TDMA, AMPS/CDMA/GSM, GSM/IMT-2000, or even AMPS/TDMA/CDMA/GSM/IMT-2000, the cost of these handsets will always be higher than the cost of a single-mode handset. Thus, not everyone will have a multimode handset. By making the BS multimode, any roamer that enters the system can be offered service. The BS must transmit a pilot signal for each type of air interface that is supported on the BS. TCHs would then be assigned depending on the number of users that request calls on each air interface. This type of BS could be designed in hardware. Unfortunately sufficient hardware (channel elements) would be needed to permit all channels to be assigned to a particular air interface. By designing and implementing the BS in software, each channel element could be dynamically reconfigured to the appropriate air interface as needed. Software defined radios, as with all wireless digital communications devices, must at some point convert their discrete and digitized information stream into analog form for transmission and vice versa for receiver. So on the practical side of this thesis, we adopt a multi-stage ADC, to perform multi band, multi- technologies conversion, the experimental result of the Soft-ADC verify good functionality and operation of the system. Software defined radio (SDR) is an exciting new field for the wireless industry; it is gaining momentum and beginning to be included in commercial and defense products. The technology offers the potential to revolutionize the way radios are designed, manufactured, deployed, and used. SDR promises to increase flexibility, extend hardware lifetime, lower costs, and reduce time to market