DSP implementation of concurrent GSM and CDMA modems for software defined radios

Software defined radio is being considered as the way forward in designing wireless equipment that meets global requirements of hosting multiple existing and emerging standards and protocols. This technology is based on the reuse of hardware to implement the physical layer processing of multiple communication systems. In this paper we describe the implementation of GSM and CDMA modems on a single digital signal processor chip. The paper evaluates the performance of an adaptive system where two different communication protocols exist on the same transceiver. The modem architecture contains the implementation of popular GMSK (a variant of FSK) and QPSK in order to support both GSM and CDMA systems. A commercial 32-bit floating point DSP has been used for implementing this design.