Abstract: The software defined radio (SDR) technology has changed traditional hardware radio platform, which is a flexible software defined radio platform and supports different wireless communication standards and system requirements. The field programmable gate array (FPGA) plays an increasingly important role in flexible SDR design due to its flexible programming features, increasing processing capacity and scale of logical resources. Starting from the design idea of software defined radio, this paper describes the design and realization of a digital down-conversion SDR system based on FPGA used in personal handyphone system (PHS), and elaborates a kind of low cost SDR realization based on hard limit and RSSI amplitude restore. Simulation results verify the validity and reliability of this method.

Key words: SDR, FPGA, hard restriction