Introduction to Software Defined Radio
Software Defined Radio (SDR) is a modern and innovative approach to physical layer design of radio
systems, in which a significant portion of functional blocks are implemented through programmable
signal processors. Although the concept of SDR was first published in 1991, it was originated in the
defense sector in the US and Europe in late 1970s. The first public SDR initiative was between 1992-
1995 and a programmable processor was employed to emulate more than 10 existing radios, operating in
frequency bands between 2 and 2GHz.
SDR methodology enables a new degree of flexibility in wireless systems design. The radio operating
parameters in SDR systems can be modified through software. The traditional analog blocks like filters,
mixers and modulators and digital functional blocks that are typically hardwired in ASIC are all
implemented in software on a programmable signal processing platform. A classic radio system is tailored
to one predefined application with very limited programmability and can only be modified through
physical intervention. This results in minimal flexibility in supporting multiple waveforms. On the other
hand, SDR technology offers an inexpensive and efficient solution to this problem, allowing multi-mode,
multi-band and/or multi functional wireless devices that can be enhanced using software upgrades.
This workshop will provide an overview of SDRs and employ current developments and implementations
to discuss the benefits and unique challenges of SDR development and deployment. The programmable
baseband signal processing aspects of SDRs will be emphasized and multiple practical examples and
case studies of soft physical layer development of WiMAX, W-CDMA and GPS will be reviewed.
Afshin Niktash received his Bachelors degree in 1995 from Sharif University of Technology and Masters
degree in 1998 from University of Tehran, both in Electrical Engineering- Electronics. In 2000, he was
awarded a fellowship and joined the Advanced Computer Architecture Lab at University of California,
Irvine where he received his Ph.D. degree in Electrical and Computer Engineering in 2006. He was a
senior engineer and the Director of Communication Systems at Morpho Technologies, CA, USA between
2001-2007 and led the development of a soft mobile WiMAX solution on a reconfigurable DSP platform.
Between 2007-2008 he was the Director of Product Development in TiaLinx , CA, USA and lunched the
first portable Ultra Wide Band RF imaging system. He is currently the President of Nikcom Consulting
firm. Afshin Niktash ranked 2nd in universities entrance exam in Iran in 1990. He has 6 filed patents and
multiple publications on reconfigurable architecture. His research interests include Reconfigurable DSP
architectures for digital communication and signal processing and Ultra Wide Band radars.