Software radio 2G & 3G inner receiver processing

Software definable radio technology potentially provides the flexibility and adaptability to support CDMA/TDMA access methods in a single radio/modem architecture. The consistent improvement in integrated circuit technology has resulted in the cost-effective realisation of 'digital' single-mode radios, some of the functionality being implemented in software. The software implementation of chip and symbol rate radio processing and the transfer of more functions into the digital domain is one aspect of software radio and was the subject of the ACTS FIRST project. ACTS FIRST attempted to extend the transfer of more functionality to the digital domain, and establish the implementation feasibility of a radio where all aspects of the air interface are implemented in software that are adaptable to different access methods. Thus, it examined a multi-mode terminal capable of supporting both DCS and Frames Mode 1B. This paper extends the work of ACTS FIRST in order to examine IS-95 and UMTS W-CDMA. The baseband implementation section briefly discusses how further improvements in DSP performance are achieved now that the lower limits in power dissipation are being reached and how A-D converters limit the implementation of software definable radios. Then, an initial treatment of software radio implementations of DCS and FMA1B is followed by a more detailed study of UMTS. A brief comparison of the front-end complexity of IS-95, the only existing CDMA cellular standard, and W-CDMA is made. Complexity estimates are derived for two different bit rate services. Furthermore, these estimates are compared to those of FMA1B.