Reconfigurable Radio Case Study: A Software Based Multi-standard Transceiver for

N a near future, base stations in Europe and Japan will have to support at least the following communication standards: GSM, EDGE, UMTS-FDD and UMTS-TDD, adding BlueTooth for terminals. A software radio (SWR) approach should permit to make substantial savings by avoiding the duplication of the entire radio systems in the equipment. This will be beneficial for both OEMs and network operators and consequently for the final user. SWR consists in taking advantage of the re-configurability properties of properly designed digital systems in order to implement all these different standards with the same components. In this paper we shall describe a case study of the Reconfigurable Radio approach which consists in using a unique hardware platform for the implementation in software of the modulation/demodulation (referred to as modem for brevity) schemes of various standards. The standards under consideration are: GSM/EDGE/UMTS/BlueTooth. Such a choice is very interesting in many aspects. First, it addresses the scenarios of standard transition and operation in multistandard environments. Second, considering all these different modulation schemes (PSK, FSK, constant envelope, frequency hopping etc.) permits to gain a better insight and a global view of the modulation topic in multi-standard equipment. The rest of the paper is organized as follows. First modulation aspects will be reviewed for a multi-mode GSM/EDGE/UMTS and BlueTooth transceiver. Emphasis will be given on several theoretical aspects which permit to obtain efficient digital implementations. The generic platform used as a proof of concept will be presented, followed by the mapping of the software on the hardware. The last part deals with performance, in terms of signal quality and speed of execution. Finally, some conclusions are drawn regarding the future of the Reconfigurable Radio approach, its deployment applications and challenging topics for future studies.