A Software Re-configurable Architecture for 3g and Wireless Systems

Software radio systems are potentially the next main improvement in mobile and wireless communications. The software radio techniques in handset design are facilitated thanks to technology evolution. The capability of such systems to support re-configuration in response to operator requirements is essential if the true potential of mobile communications has to be perceived. Moreover, customer expectations for new applications can be economically fulfilled by terminal and service reconfiguration. This paper will investigate a way to provide a flexible mobile computing and communication environment, where a user can choose between a WLAN network and a GPRS or a UMTS network, according to his current preference. Recently, a lot of IT industries and customers increased their demand for an “always on” elaboration system (computer, cellular, and even household appliances connected to a communication network). UMTS is a standard conceived for satisfying such demand with a proper trade-off. The delay that UMTS has accumulated clearly advantages the standards currently present in the market, such as IEEE802.11/b, Bluetooth and GPRS. An integration of these standards into a single terminal is necessary to avoid the multiplication of appliances predestinated to a short market lifetime and to a limited and uncertain success. This paper also concerns some issues about the reconfigurable terminal for these standards and will provide a possible hardware solution that uses the software radio technology. Introduction to software radio The challenge of third generation (3G) mobile communications has considerably pushed the research towards the Software Radio. The presence of various standards for wireless communications and the great difference of services offered by mobile communication providers has led to the planning of a universal connection, that adapts itself to different requirements. The software radio terminals must be auto re-configurable, in order to match the different telecommunication standards [1]. Software Radio (SWR) defines a radio system which has an operating range, bandwidth, level of power, type of modulation, channel coding and so on, all of them configurable by software without changing the hardware. Main rewards of a Software Radio terminal are: ü The marketing of a single product able to satisfy different customers through a software update. ü The support to the products can be simplified, and the hardware repair made easier. With the great variety of services that will be offered with 3G, the distribution will assume a remarkable role to interpret customer moods. ü For the customer, probably, it will be both a benediction and a curse: the strong dependence of the products from the software obliges the user to frequent updates, to always be able to utilize new services available from the provider. An exact definition of the SWR concept doesn't yet exist, even if the need to precisely clarify what is intended for SWR has been claimed from many people. In this framework, an approach has been developed for the implementation of different standards on a reprogrammable platform for the systems, at the baseband. Nevertheless, for the implementation of a complete transceiver, which supports all these standards, there are other parameters that have to be considered: the frequency band and the bandwidth of the radio channel; the management protocols of the different standards; different applications for the users [2]. The ideal scheme of a software radio terminal is shown in figure 1.