A combined analogue+ digital software defined radio receiver front-end for Bluetooth and Hiperlan/2

The number of wireless communication links is witnessing tremendous growth and new standards are being introduced at high pace. However, circuit development is costly and time consuming due to mask costs and design iterations. Moreover, with ever-increasing radio standard complexity, these costs are increasing. This pleads for a Software Defined Radio approach, in which one piece of flexible radio hardware is re-used for different applications and standards, downloadable and under software control. A software defined radio receiver can -at different times receive signals of a multitude of standards, obliviating the need to design, manufacture, stock and carry around separate receivers for all contemporary radio standards. The presented design includes both the analogue and the digital front-end. A CMOS integrated analogue downconverter containing a low-noise amplifier, downconversion mixers and filters performs all analogue processing required between RF pre-filters and the analogue-to-digital converter. The real-time baseband processing is partly implemented on an ASIC (channel selection) and partly on a standard PC (demodulation). Using a standard PC further enhances the flexibility of the design. The combined set-up is capable of receiving both Bluetooth and Hiperlan/2 signals. We conclude that an analog wide-band front-end with a flexible Sample-Rate Converter (SRC) combined with appropriate software on an inherently flexible PC forms a feasible architecture for Software Defined Radio.