Abstract : Digital downconversion technology has been widely used in software radio. This paper introduces the design of an intermediate frequency software radio receiver using the digital downconverter Hsp50214. This system has the functions of changing signal from analog to digital, downconversion, synchronization, and demodulation, and has certain practicality. Keywords : Software radio; Programmable digital downconverter; Programmable digital phase-locked loop; Digital signal processor [b][align=center]Software Radio Receiver based on Digital Downconverter Hsp50214 LIU Yi, FU Feng-lin, LI Chao (College of Communication Engineering, Xidian University, Xi'an 710071, China)[/align][/b] Keywords: Software radio; Programmable downconverter device; DSP; 1 Introduction Software-defined radio (SDR) can be considered the third revolution in the history of wireless communication technology. It is a highly digitized, fully programmable, and easily expandable communication system. Its core idea is to place the A/D and D/A converters as close to the antenna as possible and digitize the analog signal as early as possible, so that functions such as signal generation, modulation, encoding, decoding, and demodulation can be completed by a digital signal processor (DSP). This approach typically presents a problem: signal sampling is usually at or above the intermediate frequency (IF), resulting in a sampled signal generally above tens of MHz. This makes it difficult for conventional DSPs to process such high-speed digital signals. The solution adopted is to first downconvert the high-speed digital sampled signal output from the A/D converter to a low-speed baseband signal, which makes the DSP more capable of handling it. [b][align=center]For more details, please click: Software Radio Receiver Based on Digital Downconverter Hsp50214[/align][/b]